Hogwarts? How Serendipitous!
by Nassy Nyrolian
Summary: After Ferb receives his Hogwarts letter, Phineas, (a Muggle) becomes disheartened and stowes away in Ferb's suitcase to accompany him. After making a few friends and a few enemies, they learn of something odd with a Sorcerer's Stone. Ferb takes along Perry for his pet, and so Dr. Doofenshmirtz follows so Perry can foil his evil plot. Takes place during first book. Read and review!
1. The Very Beginning

"Look at _THAT," _Candace proclaimed, shoving her mother out into the yard and gesturing proudly with a hand.

Linda Flynn squinted her eyes. A shocked expression crossed her face.

"Uh huh, uh huh," Candace said quickly, her hopes rising, that this was the fateful day...

"Did Phineas and Ferb do that?" Linda squeaked, her mouth dropping open.

"You see it?!"

"No, honey, I don't see anything," Linda said calmly, turning around to go back in the house. "But it made for an exciting introduction to the story, don't you think?"

Candace stood in bewildered, awkward silence.

"_Meep_."

Her brothers, Phineas and Ferb glanced idly around the yard.

"How intriguing," Phineas stated. "The world's largest waffle seems to have vanished. It was here just a moment ago."

A semi-aquatic, egg-laying mammal scurried to Phineas's side. His teeth chattered together in the typical noise made by a platypus.

"Oh, there you are, Perry," he added, picking up his pet. He lifted Perry up higher and examined him from every angle. "Maybe Perry ate it," he hypothesized.

Ferb blinked. "If he did, we'd have to start calling him Perry the Fatapus."

"Wh..wh..wh..where is it?" Candace stammered, running from one side of their backyard to the other in a panic. "It was here! It was just...just...just _**here**_!"

High above in the sky, unseen by any member of the Flynn-Fletcher family, an enormous waffle dangled from a fishhook, hanging from the bottom of a hovercraft.

"What the – a _waffle_?" Dr. Doofenshimrtz asked incredulously. "NOOO!" he cried, as the weight began to drag his machine rapidly towards earth. "_CURSE YOU, PERRY THE PLATYPUS!_"

"What a shame," Phineas said, shaking his head as he went inside for a snack. "I was looking forward to eating that tonight. Well, it's not _that _big of a deal, right, bro?"

Ferb hesitated for a moment. Should he tell his stepbrother? That _feeling _he had, whenever their creation for the day vanished. It was a feeling that was indescribable, but the closest he could come to was... well, _magical._ But he eventually raised his hand in a thumbs-up.

Little did they know it was the beginning of the greatest adventure of all...


	2. The Letters From No One

"Morning, Ferb."

Ferb nodded in response to his stepbrother's salutation. He then pointed to their door and rubbed his stomach.

"You're right, bro! Mom's making bacon and eggs today," Phineas remembered, growing hungry. But his face fell into a frown. "I still feel bad about that waffle, though."

Sighing, Phineas laid down on his bed again. "What happened to that, anyway? It was there, I looked away for a second, and it was gone! Like, _poof_, magic. It's not that I object to our inventions vanishing," he specified, talking to his brother, "but I wonder what happens to them every day? I mean, there has to be a logical explanation. Even if there was, why does it happen _every day_?"

Ferb stared at him, as unresponsive as the bedroom floor.

"Exactly, Ferb!" Phineas exclaimed. "It doesn't matter _what _is taking our inventions away. What _matters _is the fact that it happens _every day_! It seems odd, once you think about it. It's like...like magic, almost," he said. "And there's no hint of foreshadowing in that statement," he added.

Phineas and Ferb slid down the railing and joined their family at the breakfast table.

"Morning, boys," their fine English father greeted, picking up the newspaper. "Hmm, giant waffle sightings in the sky yesterday...how peculiar..."

"Morning, Dad," Phineas said, sitting down at his place and filling his bowl with cereal. He added milk and stirred it around in his bowl, making loud clanking noises.

Candace covered her ears. "Hey, keep it down, dweeb!" she commanded.

Phineas stopped.

The clanking continued.

Linda Flynn-Fletcher turned around, her eyes widening to dinner plates. "What the –?"

A barn owl, holding something white and flat in its beak, was pecking at the window frame. It looked at them with what could have been exaggerated patience and continued.

"What...what is _that_?" Linda asked, shrinking back in her chair.

"That," Ferb said in his clever English accent, "is a specimen of _Tyto alba, _of the Family _Tytonidae _and Order _Strigiformes." _

Candace stood up, letting her breath out in a frustrated huff. "Okay, people, I'll be the one to get up and shoo it away." She opened the window and waved a hand at the owl.

"Hey, you! Ya overgrown pigeon, _beat it_!"

The owl hooted loudly and swooped in through the window. Candace ducked and covered her head, squealing. "_AHHHHHH! Get it off, get it off, get it off!" _

The owl circled around the kitchen table for a few moments, with the family watching, not exactly sure what to do. It hooted again and dropped what it was carrying above the center of the table, before exiting through the window again.

Falling in the way that paper does, it sliced back and forth in the air, slowly fluttering down and landing.

On the plate of Ferb Fletcher.

As if this was a completely normal occurrence, Ferb took the letter and brushed bacon crumbs off of it. In the awkward silence, the _riiiipp _of the envelope tearing seemed like the house was being torn in half. He removed the letter inside, read it quickly, and passed it to his brother Phineas.

"_Ferb Flynn-Fletcher_," Phineas read slowly. "_You have been accepted into Hogwarts School of Witchcraft and Wizardry_."

Silence claimed the table again.

"Ferb's getting warts?" Candace asked, puzzled. Her eyebrows collided in a frown. "I _told you_ not to touch that bullfrog last week!"

"No, no, _Hogwarts_," Phineas restated, standing up and showing the letter to the rest of the family. He glanced at Ferb. "Did you apply for something like this?"

Ferb shook his head.

"This has got to be some kind of joke," Linda asserted, taking the letter. "Right, honey?" she asked Lawrence.

Lawrence's face had turned a shade of embarrassed pink. He laughed nervously.

Linda frowned. "Lawrence, do you know anything about this?"

He laughed again. "A bit, dearest," he answered weakly.

"Dad?" Phineas asked, his eyes widening. "What's going on?"

"Erm...um...well," he began, tugging nervously on his shirt collar. "I suppose I should explain a few things..."

"Before I met you, Linda," he said, "I had Ferb, as you know...Well, his mother wasn't...wasn't really...I mean, she was...it's hard to explain..."

"_Lawrence_..." Linda said threateningly.

Lawrence sucked in a breath.  
"_Ferbsmotherwasawitch_," he said in one breath, intentionally faster than anyone could register.

Linda blinked. "What?"

"Ferb's mother was a..._witch_," he said, convulsing slightly at the last word. "We met at an antiques convention in Blackburn. She said she was fascinated by those sorts of things...I thought she meant antiques," he added lamely, laughing again. "But no, she meant Muggle things..."

Phineas blinked. "Muggle things?" Ferb hopped out of his chair, and they stood on either side of their father.

"_Muggle_ is what wizards and such call us _normal _people," he explained, patting his stepson and son on the shoulders, as if it would help ease the realization. He turned to Ferb.

"I'm so sorry, son...I didn't know that this would happen...she _did _mention a school," he added. "I thought that it might go away if I didn't do anything."

Ferb looked up at his father.

"Oh, your mother? Your mother was incredible – witty, good with her hands, despite being a witch, and interested in our technology." He looked down at the ground, just then, and folded his hands in his lap.

"But she also loved adventure, my boy, and one day, went with her sister, who worked with magical creatures...She was confused about what a fire extinguisher was, and thought it was a wand that protected her from fire. Her sister was helping to capture a dragon for some kind of festival, and..." Lawrence bit his lip and patted Ferb's shoulder again.

"Ferb," Lawrence resumed, looking seriously at his son.

"In conclusion...I know this is a bit of a shocker, but...you're a wizard."

Ferb blinked. He paused for a second. "Okay," he said coolly.


	3. Candace Rejoyces

"Whoa, whoa, whoa, whoa, whoa, _hold the phone_!" Candace said, putting her hands up as it to stop this oncoming train of revealed truth. "Wizards aren't real!_ Magic isn't real_!"

"I'm afraid so, Candace," Lawrence Fletcher said. "I've seen it done. And I suppose that now Ferb is due to attend this Hogwarts school..."

Phineas walked away from his father suddenly and, standing on his tiptoes, peered out the window and into the sky. He turned back to the family. "Mom, where's my letter?"

"I am pleased to say that you, at least," Linda answered stiffly, "are completely normal. Your father wasn't a wizard. He was a pharmacist. At least, I think..." she said, putting a finger to her chin in thought.

"What? I'm not a wizard?" Phineas asked with disbelief. "But Ferb's going off to Warthog school! We've always done _everything _together! Always! Can't I go with him?"

"I'm awfully sorry, Phineas," Lawrence said. "But Ferb's mother once told me that only wizards and witches can attend this school. You're not a wizard."

"I should _think_ not," Linda grumbled, still mad at her husband.

"What's the list say?" Phineas asked, crowding around his brother. "Scales, vials, books...robes and a pointed hat?" he asked, holding the paper at arm's length away from him. "What, are you all pharmacists or something?" His eyes found the last item on the list, and he gasped. "A wand? He gets a _wand?_"

Candace glared at the note. "Wait a second!" she proclaimed, ripping the list from Phineas. "It says they attend this school when _they reach the age of eleven_. What do you say to that?"

Linda stood up and, placing both palms on the table, exploded at her daughter. "WELL, CANDACE, CAN _YOU _TELL ME HOW OLD THEY ARE?"

Candace looked from Phineas...to Ferb...back to Phineas...

The boys smiled.

"Point taken," she grumbled, thrusting the list back at Phineas. "Well, at least that's _one_ fewer freak I have to bust. And it explains the whole idea of the Mysterious Force – Ferb has magic."

"Can't I come?" Phineas begged. "Please! I'll do _anything_!"

"Sorry, Phineas, it can't be helped," Lawrence Fletcher repeated. "It'll still be fun at your regular school, eh? The teachers, the students, the cafeteria food..."

"You get to buy a pet!" Phineas shouted, holding the list out in front of him again. "An owl, cat, or frog, it says! I want an owl," Phineas whined, sitting down in his chair again.

Ferb held his hand up, as if asking permission for silence so he could speak. When silence ensued, he pointed questioningly at the pet platypus sleeping on the floor.

"You want to take Perry?" Phineas asked. He turned upon his stepbrother. "Okay, that's the FINAL STRAW, bro! First, you shove in my face that I'm not a wizard, dad threatens me with cafeteria food, and now you want to take away my platypus? I don't think so!"

Phineas crossed his arms and ran upstairs to his room. A door slammed.

"And there goes the second freak," Candace observed with a smug smile. "This letter might be the best thing that ever happened to me."


	4. At OWCA Headquarters

A/N: I do not own Harry Potter or Phineas and Ferb

At OWCA Headquarters, Francis Monogram picked up the phone. "Hello?"

"Hello, Francis. It's me, Heinz..." Dr. Doofenshmirtz said, calling from his building at Doofenshmirtz Evil Incorporated. "Have you...um...seen Perry the Platypus lately?"

"Perry the Platypus is unavailable for foiling evil plans right now," Francis explained. "Uh.. just out of curiosity, what evil plan do you have for him?"

Dr. Doofenshmirtz proudly held up a handheld device. "I call it...the Duct-Tape-Inator! I realized a few days ago that I get _sooo _tired when people talk for a long time to me, so I invented this Duct-Tape-Inator to put Duct Tape on their mouths when I want them to stop talking!"

"Okayyy..."

"Francis, where _is _Perry the Platypus right now?" the evil scientist asked curiously.

"Agent P is currently in England, at some sort of school at the moment. We've sent Agent S. to take his place."

"Great!" Dr. Doofenshmirtz exclaimed. "When...when will he get here?"

"We have video feed for you to track Agent S's progress."

Dr. Doofenshmirtz picked up a TV remote and turned on the large screen on which he would have shown Agent P. today's tragic backstory. Black and white zigzags flickered across the screen, before showing the front drive to the OWCA headquarters.

A sloth was creeping its way down the drive.

It lifted one claw...

It put down the claw...

It pulled itself forward a few inches...

It lifted another claw...

It put down the claw...

It pulled itself forward a few inches...

"We expect he'll make it to your headquarters to thwart your plan in about...oh, three or four years," Francis Monogram said through the telephone. "We apologize for the inconvenience, but every other agent was out for the day."

He hung up.

Dr. Doofenshmirtz turned back to the big screen.

Agent S. picked up one claw...

He put down the claw...

He pulled himself forward a few inches...

Dr. Doofenshmirtz sighed, and walked off to his kitchen countertop, shifting the pile of stuff on the counter around.

"Yeah... where's my passport?"

A/N: More coming soon, I promise, if in fact anybody is reading this (which I doubt). It _will _get better; in the next chapter the action will pick up!


	5. The Train and the Toad

A/N: Just wanted to get into the Hogwarts school year without wasting time with extra or long chapters that might deter the short attention span of a reader. (Because, believe me – their attention spans are next to _nothing_ when it comes to long chapters.) I do not own Harry Potter or Phineas and Ferb. I would also like to say that I do not get to watch Phineas and Ferb on TV, so the only things I can reference are the episodes on DVD, Across the Second Dimension, and the occasional episode at a friend's house. That being said, enjoy the story!

Linda, Lawrence, and Candace waved from their bench. The train whistle sounded, the train gave a little lurch before setting in motion. Phineas was still in their hotel, sulking about Ferb's opportunity and abilities.

"Don't forget to write!" Linda called, as Ferb was carried away with the train. "We'll come pick you up if you ever, _ever _feel unsafe, or hungry, or anything!"

Ferb gave them the thumbs-up. He waved leisurely as the train picked up speed and they fell behind him.

He looked around for a compartment to sit in. Most of them were full of children. One in the back, though, only had two boys in it currently. Ferb picked up his suitcases, walked to the compartment, and slid the door open.

There were two very surprised-looking boys inside. One, with blazing orange hair, was holding a grey rat, which looked sick. The other had very distinctive black hair and glasses, with some sort of mark on his forehead.

Ferb, not saying a word, pointed questioningly to the empty seat next to the ginger.

"Oh...um...sure, mate..." the boy said, moving over to make room.

Ferb set his suitcases in the shape of stairs and used them to climb up to the seat. He pulled out _The Odyssey _by Homer and began to read in silence.

"Er..." the ginger said. "My name's Ron...Ron Weasley..."

Ferb nodded politely.

"I'm Harry Potter," the black-haired boy said.

Ferb nodded again, turning a page in his book.

"What's... your name?" asked Harry, adjusting his glasses.

In response, Ferb pulled out his Hogwarts welcome letter and handed it to him.

"Ferb Fletcher?"

Ferb nodded again.

"Do you..._talk_?" Ron asked, pulling a little further away from him.

Ferb blinked. "Only when something needs to be said," he remarked, before going back to his book.

Suddenly, one of Ferb's suitcases began to quiver violently, before the clasps _EXPLODED _open and something leaped out in a shower of clothing.

"_BLOODY HELL_!" Ron screamed, jumping out of his seat and backing against the window. Scabbers was desperately trying to climb the luggage rack, and Harry scrambled up so that he was standing on the seat, breathing heavily.

Phineas Flynn brushed a purple pair of shorts off of his shoulder. "Surprise!" he announced.

"Who're _you_?" Ron demanded.

"I'm Phineas, and that's my brother, Ferb." He threw Ferb's things back in his suitcase and joined his brother on the seat.

Harry stared at Phineas. "What were you doing in his suitcase?"

"Stowing away," Phineas replied happily, thrumming his heels against the seat. "Mom wouldn't let me come because I wasn't a wizard, but that's not stopping me from being with Ferb! We'll have the best time ever, right, bro?"

"You're a Muggle?" Ron gulped.

"Yup!" Phineas leaned back in the train seat. "But that's inconsequential. Ferb and I are gonna have the best time _ever _at this magic place, Warthogs, I think."

Ron looked at him with what could have been a trace of disgust. "Hogwarts."

"Whatever."

A lady opened the compartment door, towing a cart full of delicious-looking sweets. "Anything off the trolley, dears?" she asked sweetly.

Ron mumbled something about a sandwich.

Harry, on the other hand, withdrew a handful of what looked like gold coins and said, "We'll take the lot!"

"_Someone_ has a sugar problem," Phineas whispered to Ferb.

Harry and Ron eagerly tore into the sweets. Ferb continued reading _The Odyssey_, and Phineas took a handheld video game out of Ferb's suitcase.

There was a knock on the compartment door. Phineas hopped of the seat and opened it.

"Oh, you're back," Harry remarked, seeing a round-faced boy who was in tears and a bushy-haired girl with him.

"Has anybody seen a toad?" the girl asked. "Neville's lost one," she said in a bossy voice.

"We're already said we haven't seen it," said Ron.

"A toad?" Phineas asked. "What species?"

"I...I dunno..." Neville sobbed. "He was...brown and...blackish with...I dunno..."

Phineas snapped his finger and shook his brother by the shoulders. "Ferb, I know what we're gonna do today!"

The bushy haired girl watched them oddly. Phineas clambered up the seat and, withdrawing a screwdriver from his pocket, began taking apart the luggage rack above them. "Ferb, I'll need extra-strength glue, two lollipops, some of those moving frog things, a fan, and a drop of sugar water placed on the windowsill."

Ferb gave a thumbs-up. He took some of the sugar-flavored Bertie Bott's beans and crushed them into powder. He picked up a glass, handed it to the girl, and blinked.

"Oh, you want some water...?" She picked up her wand. "Er...I think it's..._Aguamenti_."

A trickle of water escaped from her wand. She filled it up a fourth of the way and handed it back to Ferb. He mixed in the sugar beans and smeared a drop on the windowsill, and also a drop of glue from a bottle he had with them.

Harry, Ron, Neville, and the girl watched quizzically. A crowd began to form outside of the train compartment.

A few flies that were buzzing around the compartment were attracted to the windowsill and became stuck in the glue. Ferb used a tweezers to pick them loose and attached them to one side of each lollipop. Phineas handed him a short, metal pipe from the luggage rack and fixed the lollipops on so that they would snap shut with weight. Then, they took the small contraption outside the compartment.

The group of students followed curiously.

Phineas and Ferb placed the fly-baited instrument on the floor, and let loose a number of Chocolate Frogs, to "create an environment that seems safe and natural," Phineas explained. He then instructed everyone to step away from the contraption, and used a fan to waft the fly aroma around the room.

"Trevor!" Neville yelled out, spotting his toad amongst the chocolate ones on the floor. Ferb reached out and stopped him before he charged forward.

"Wait for it," Phineas said.

Trevor hopped to the trap and, smelling it cautiously, tentatively stepped between the lollipops.

It snapped shut like a mousetrap, with Trevor squirming to escape, but only managed to get toad slime all over the lollipops.

The crowd gave an excited cheer, and Neville came forward to take his toad back. Phineas and Ferb gave a small bow to the cheering mass of students, and took apart the contraption while the crowd disbanded.

The girl watched them disassemble the trap. "Wow, that was clever," she said, looking impressed. "I'm Hermione Granger," she introduced, shaking Phineas and Ferb's hand.

"Thanks for Trevor," Neville said graciously, beaming from ear to ear. He slid the toad into his pocket and walked away.

As he was walking, three boys, all with ugly snarls on their face, made it a point to bump into him when they went past. "What's all the noise about?" a platinum-haired boy demanded, looking to be the leader of the threesome. His eyes glanced at Harry's face, and the snarl was replaced by a brief look of wonder.

Replacing the snarl, the boy walked up to Harry. "You're Harry Potter." It was not a question.

"Er...yeah," Harry said nervously.

"I'm Malfoy. Draco Malfoy."

Ron gave a cough that might have hidden a snigger.

"Find something funny, do you?" Draco asked, glaring at Ron. "No need to tell me _your _name. My father told me all Weasleys have red hair and more children than they can afford."

"Hey!" Phineas exclaimed.

Draco looked at Phineas and Ferb. His mouth dropped open. "What are _you_?"

"I'm a cartoon character," Phineas said coolly, crossing his arms. "You got a problem with that?"

"No," Draco said quickly, and turned back to Harry. "If you hang out with scum like the Weasleys it starts to rub off on you. When you make friends, you've got to be careful who you chose. I can help you there," he said, extending his hand for Harry to shake.

"I think I can choose my friends by myself, thanks," Harry said dryly.

Draco pulled his hand away, disgust crossing his face again. "In that case, we've come for an entirely different reason. Someone told us that the candy trolley had been emptied. And, seeing that we've eaten all of ours..."

Ron looked ready to shout at Draco and his gang, but before he could, Ferb dashed forward and handed Draco two lollipops.

"There you go," Phineas said, stepping next to his brother.

Draco smiled. "That's more like it." He walked back to his compartment through the hallway, and everyone else, who had seen the trap for Trevor, stared as he ate the lollipops coated with toad slime.

Harry, Hermione, and Ron turned to the brothers again.

"What'd you say your names were again?" Ron asked wondrously.


	6. Phineas's Wand (Of Sorts)

A/N: I do not own Harry Potter or Phineas and Ferb. Now that that's said, read the story!

"Wait, so you're a Muggle?" Hermione asked with a completely disbelieving look. "What are you doing on this train?"

"Well, obviously, I'm riding to Hogwarts," Phineas answered with a shrug.

Hermione shook her head. "No, no, that's bad, Phineas. You _can't _go to Hogwarts because you _can't work magic._ I'm sorry, but you need to stay on the train until it rides back to King's Cross."

"Aw, a little thing like being a Muggle isn't going to stop _me _from being with Ferb," Phineas said, elbowing his brother. "I mean, we've done everything together through the summer. We built a rocket, we fought a mummy, we climbed the Eiffel Tower, we discovered something that doesn't exist..."

"Stop reciting your title sequence!" Hermione snapped. "The point is, you can't fake magic. When our Transfiguration teacher asks you to take out your wand and turn a matchstick into a needle, what are you going to do?"

"I'll turn a matchstick into a needle," Phineas replied smugly.

Hermione huffed and put her hands on her waist. "How, exactly?" she asked exasperatedly.

"Easy," Phineas said. He hopped off the stool and rubbed his nonexistent chin in thought. "I'll need a piece of wood from the seat, my video game, that chocolate frog, and some glue."

Ferb obediently slid off the seat and began gathering the items listed.

"What are you doing, mate?" Ron asked as Ferb tore a strip of wood from the train seat.

"Oh, just building a wand," Phineas replied breezily while he dismantled his handheld video game. "I have all the pieces I need right here in this compartment." He hummed the "_Those Boys are Evil_" song while he worked.

Ferb handed him the strip of wood, which Phineas cut in half. He then carefully inserted choice wires and electronic devices in the center. Ferb had set up a laboratory station and was doing something with the chocolate frog.

"You see," Phineas explained like a lecturing professor, striding back and forth in front of Harry, Ron, and Hermione, "technology doesn't work in Hogwarts, right? Too much magic in the air."

"Hang on, how do _you _know that?" Hermione demanded.

Phineas blinked. "Oh, didn't you tell us yet?"

Hermione checked her copy of the script. "I'm not due to tell you until the next chapter!"

Phineas waved a dismissive hand. "Let's not dwell on these trivial matters. Like I was saying, the chocolate frog has a magical enchantment cast upon it. If we break the frog down into its primary chemical components and perform quadratic functions to the atoms to the third degree and rearrange the placement of electrons, and then infuse these newly modified chemicals into the wand, we can "temper" it, so to speak, to magic, so it can operate in tandem with the magic in the air even though the opposing polarity of the electrons would otherwise disrupt the signal!"

"You...might want to close your mouth, Ron," Phineas said kindly. "Although I _do_ appreciate the gesture."

Phineas and Ferb poured the something-or-other of the chocolate frog onto the electronic components, which sizzled, and sparks came flying out. Then, he closed the wand and glued it shut.

"But does it _work_?" Hermione asked furiously. "It won't work. You can't duplicate magic. You can't do it."

Phineas cleared his throat. "Wand, initiate bonding of two hydrogen and one oxygen atoms."

"_Initiation underway_," his wand replied, and everyone but Phineas and Ferb jumped.

A fair spurt of water came out of the tip of his wand.

"Wand," Phineas continued, basking in the looks of wonder that Harry, Ron, and Hermione were displaying, "set command: previous, equal with command, _Aguamenti_."

"_Command set. Have a nice day, Phineas."_

He pointed his wand and said, "Aguamenti!" More water came streaming out, as before.

"Wow!" Harry said, unable to help himself.

"Wicked!" Ron exclaimed.

"_What_?" Hermione asked, unbelievably, rushing up to the wand and examining it. "But...but...you...but...wand...but..._what_?"

"I'll have to program it with a spell," Phineas admitted, "but that's a small price to pay for magic!"

"_IT ISN'T MAGIC_!" Hermione nearly screamed. "I don't want to be rude, but... you _don't belong at Hogwarts!"_

"She's just jealous," Ron told Phineas. "Thought she was _so smart_, until now."

Harry laughed again. "Wow... just, wow. You're amazing, Phineas."

Phineas gave a little bow. "I express my appreciativeness."

"Can't you talk normally, just for a few moments?" Hermione huffed again. "Honestly, one of you doesn't speak at all and one of you talks _way_ too much."

"Hey, Ferb, what's _your _wand?" Harry asked curiously.

Ferb took his wand out of his pocket for Harry to examine.

"Phoenix feather and pine," Phineas said for his brother.

"I've read loads about them!" Hermionie interjected quickly. "Pine wands are the most sensitive wands to nonverbal magic!"

There was an awkward silence as everyone in the train compartment stared at Ferb.

"How applicable," Phineas noted.


	7. A Brief Interlude with Perry

A/N: I do not own Harry Potter or Phineas and Ferb.

"Whoa!" Ron suddenly exclaimed, looking at one of Ferb's cases. "What's that? You might want to get rid of it; it might be breaching the Ministry code against illegal breeding."

Ron was pointing at Perry in his cage. Phineas opened the cage, despite Ron's protests, and brought the pet on his lap. "Oh, this is Perry, our platypus. He doesn't do very much."

Hermione looked at the animal sideways. "You have a pet platypus?"

"Do you want to hold him?" Phineas asked, extending the platypus for Hermione to take. She backed away, forcing a smile.

"No, no, that's okay."

Phineas extended Perry for Ron to take. He tentatively complied, and set him on his lap.

"He doesn't do much, right?" Ron asked nervously.

Suddenly, Perry began to squirm in Ron's hands. Ron dropped him and backed up against the wall again, in utter terror. "_WHAT'S IT DOING? WHAT'S IT DOING?" _he squealed.

Perry made his platypus chittering noise.

"Oh...oh, that's it, then." Ron was obviously relieved, and took his seat again, pushing Perry back to Ferb with his foot.

When Ferb reached down to pick him up, Perry scampered out of reach and squeezed through the compartment door.

"Where's he going?" Harry asked.

"No idea," Phineas said happily. "But if he could get himself out of here, he can himself get back in."

Once Perry had slipped through the door, he stood up on his two hind legs and put on his trademark fedora.

_He_ had become Agent P.

Silently, Agent P. ran through the train's hallways until he reached a ventilation shaft, which he climbed into. Inside the dark shaft, he activated the portable communication device in his watch.

The image of Major Monogram flickered in the darkness. "Good morning, Agent P," he greeted.

Perry blinked and showed the Major a picture of the sunset outside.

"Agh, I forgot. Darn time difference," Major Monogram muttered. "Anyway, we at the Agency heard about your little...ah...trip, so to speak. We're afraid that the fun will have to stop here. Doctor Doofenshmirtz, your arch nemesis, has been up to no good again."

At his words, a picture of the demented scientist popped up on the screen.

"We have, through our best, top-secret intelligence agents, found that he has created a device that will put Duct Tape over whatever he wishes. While this does seem trivial – "

"He's getting _desperate_," a young, payless intern butted in.

"Be quiet, Carl!" the Major shouted. "Anyways, Agent P, I feel obliged to tell you that Doof has followed you across the ocean, over the desert, through an undiscovered underground tunnel connecting Russia to Australia, and over Mount Everest to England."

"_Yeah_...he kind of ...got lost," the Major admitted. "But at your destination, Agent P, watch out for his shenanigans, _and remember_ – if your host family discovers your secret, you will have to leave them _forever_."

The image of Major Monogram flickered out.

Perry sat in silence for a moment, letting the horrible thought of having to leave the boys sink in a bit. He removed his fedora and climbed through the ventilation shaft until he was directly above Phineas and Ferb's compartment. Giving the shaft a small kick, the bottom opened up and Perry fell out.

Right onto Ron's head.

As Harry, Hermione, Phineas and Ferb watched Ron squeal run madly around the compartment, the two brothers looked at each other, and smiled.


	8. The Sorting (Of Sorts)

A/N: I don't own Phineas and Ferb or Harry Potter.

With a loud, _swishing _noise, the doors to the Great Hall opened. Phineas and Ferb gasped at the scale of the hall: five of their backyards could have been spread out on the floor. Four tables, under four different banners, sat on the floor. On them sat wizards and witches. They watched the first years' progress under pointed hats, following them with their eyes.

"Well, Ferb, you ready?" Phineas asked him.

Ferb gave him the thumbs-up.

"What house do you want to be in?"

Ferb shrugged. He glanced at all four banners, but his gaze seemed to snag on one in particular. Phineas couldn't tell what it was.

"I want to be in Gryffindor," Hermione told them. "That's where the brave people go. Dumbledore himself was a Gryffindor!"

McGonagall, the witch who had just informed them about all four Houses in-between chapters, stood in front of a stool and began calling off names.

"Abbot, Hannah!"

A girl stumbled out of line and tried on an old, tattered hat, the Sorting Hat, which had just sung a song that the author felt too lazy to copy down and possibly lose a reader with a very short attention span.

"_HUFFLEPUFF_!" the hat shouted. The girl waddled to the Hufflepuff table.

"Bones, Susan!" McGonagall called.

After trying on the hat, she was proclaimed a Hufflepuff as well.

More names were called, and more people sorted.

"Finch-Fletchley, Justin!" she called, and another boy was Sorted into Hufflepuff.

"Fletcher, Ferb!" McGonagall shouted.

Ferb, calm as ever, walked out of line and hopped on the stool. The Hat was so big on him that it nearly covered his mouth.

The Sorting Hat squirmed on Ferb's head. The creases and folds that made up its face were twisted in deep thought.

"_RAVENCLAW_!" the Hat finally roared. Ferb slid out from under the Hat and walked to the Ravenclaw table, which was applauding loudly.

McGonagall continued with the calling of names, until she reached at, "Zabini, Blaise."

As Blaise stepped off the stool, McGonagall was about to fold up the sheet when she happened to notice Phineas still standing there.

"Didn't your name get called?" she asked sternly.

"No, ma'am, in fact, it didn't," he answered, bouncing on his toes.

"What's your name?"

"I'm Phineas Flynn."

McGonagall looked the sheet over. "I'm afraid you're not listed here, Mr. Flynn."

Phineas blinked. "I can't imagine why not," he said, suppressing a laugh.

Professor McGonagall seemed flustered. She glanced at Phineas, back at the sheet, and then cleared her throat. "Very well, Flynn. I apologize for the error."

Phineas smiled broadly and took his place on the stool. McGonagall put the hat on his head.

It fell off.

The school sniggered and laughed; McGonagall picked the hat up again and tried to balance it.

"You do have a rather..._peculiar _head shape, Flynn," McGonagall noted apologetically, as the Sorting Hat fell off of his head again. "It reminds me of...er...a... "

"A triangle," Phineas finished for her glumly. He sighed and just held the hat in place with his hands. He waited breathlessly...

"_RAVENCLAW_!" the Sorting Hat proclaimed loudly.

"How serendipitous!" Phineas said, loud enough for the school. Half of his new House didn't even know what it meant.

Phineas hopped off the stool and ran to the Ravenclaw table in jubilation. They high-fived and waved at Harry, Ron, and Hermione at the Gryffindor table.

"Hey!" a Ravenclaw suddenly shouted, turning to Phineas. "Didn't you make a water slide down Big Ben once? I remember you!"

"Yeah, me too!" another joined in. "And then a while before that you held a jousting tournament, right?"

"Yes, yes I did," Phineas answered, pleased to be at the center of attention. "Did you come to the tournament?"

"Oh, you bet! It was incredible!"

A third-year girl stared at them oddly. "Wait...but I thought that the people who did that were _Muggles_."

Phineas's happiness fell, crashed and burned. If he was going to keep up this charade, he couldn't go broadcasting that he had done...well, everything he did. For a moment he considered owning up to it, but then the teachers would become suspicious, especially after his apparent nonexistence with the Sorting list...

"Well, yes, you're right. I _am _a Muggle," Phineas said leisurely.

The girl nodded skeptically. "Yeah, right...sorry, I could have _sworn_..." She looked at him again, scrutinizing him from head to toe, but eventually shook her head and began chatting with her friends.

Phineas smiled and turned to Ferb. "Wow. I guess the best way to lie is to tell the truth, huh, bro?"


	9. A Brief Interlude with Dr Doofenshmirtz

A/N: I do not own Phineas and Ferb or Harry Potter.

"This is where Perry the Platypus is staying?" Doctor Doofenshmirtz asked incredulously, standing on the shore of Hogwarts Lake, and gazing at the castle. To his non-magical eyes, the castle seemed run-down, unstable and abandoned. "Geesh, what a dump!

"Man, even _I've _never had a lair _this _bad," he stated, clambering into his Buoyancy Operated Aquatic Transport, or, BO-AT. He started the engine and set off from the shore.

"The trouble I've been through just so he can foil my plot!" Doofenshmirtz exclaimed, motoring across the murky water. "I've _crossed the ocean_, I've _had my BO-AT shipped _very expensively from my penthouse, I've -"

He saw something stir out of the corner of his eye. Something had moved in the dark water.

"Okay, it's creepy _enough _without weird things squirming in the water!" Doofenshmirtz shouted to the world. He started singing a song to calm his nerves.

"_Bow chick-a bow wow – that's what my baby says, mow, mow, mow, and my heart starts thumpin', gitchi-"_

Suddenly, a huge, suckered tentacle BURST from the surface of the water and wrapped around his BO-AT. Doctor Doofenshmirtz screamed and threw himself against the steering wheel, screaming and squealing. The giant squid of Hogwarts Lake was protecting the school from invaders.

More tentacles wrapped around the BO-AT, and with the strength of ten people, lifted the BO-AT into the air and kept it suspended there. There was a moment of horrible stillness when the boat was aloft in the air.

The giant squid _heaved _the BO-AT in the air and sent it flying toward shore. Doofenshmirtz squealed as it turned somersaults in the air, before crashing into a grove of trees.

"_CURSE YOU, CARRIE THE CEPHALOPOD!_" he screamed from shore, somewhat muffled by the tree.

The giant squid watched him contentedly, and adjusted the unseen fedora on his head before sinking back down in the inky black water.


	10. Phineas and Ferb Visit Hagrid's Hut

A/N: I don't own Phineas and Ferb or Harry Potter. Now READ and REVIEW!

The first week of Phineas's deception went surprisingly well. While they found it odd that he wasn't on their attendance sheets, Phineas simply informed them that he was actually a Muggle who built a mechanical wand and had stowed away on the train in his brother's suitcase.

"I'm sorry, Flynn," the reply would almost always be. "I wonder why the Ministry forgot to add you to the list of students?"

His mechanical wand, a thing of utter beauty, performed its tasks well. The only problem was that Phineas had to tell it _specifically _what to do in a scientific manner, and then set the command equal with a "spell". For this purpose, Phineas had to learn the incantation and then, to program the spell, quickly request a bathroom break.

To get rid of suspicion of his activities, he found himself forced to quaff horrific amounts of pumpkin juice at each meal.

Pumpkin juice was not his favorite hydrating substance.

Phineas and Ferb's classes were well enough. Phineas liked Professor Binns's class, the ghost professor who taught History of Magic, the best, because it was pretty much an extra hour of sleep each day. Ferb seemed fond of Potions and Astronomy, because it required so little talking on his part. They met up with Harry, Ron, and Hermione regularly.

On a fine Friday afternoon, Phineas and Ferb had just finished Arithmancy classes and were going to meet the three Gryffindors in the courtyard. Harry waved them over to a bench.

"I got a letter from Hagrid this morning; he's the keeper of the grounds. We're going to his house for some tea. Want to come?" Harry asked.

"Tea?" Phineas smiled and asked, glancing at his brother. "Man, Ferb, they don't let you forget for a second here that you're in England, do they?"

Hagrid's hut was at the edge of Hogwarts's grounds, near the Forbidden Forest. It was a bit of a walk, but they arrived in due time.

From inside the hut there came loud, fierce barking. "_Back, Fang, back_!" an equally gruff voice told the dog. Soon, the door was opened and Phineas and Ferb got their first look at Hagrid.

""Arry!" Hagrid exclaimed. "Nice te see yer! Glad you got the letter." He glanced over and happened to see Phineas and Ferb standing there.

"'An what's this? Cartoon characters! 'Arry, ye need to introduce me, here, who's this?"

Phineas and Ferb walked up and shook his massive hands. "Hi," Phineas said. "I'm Phineas, and this is my brother, Ferb! I believe we gave a shower to one of your northern kinsfolk in our Christmas episode title sequence."

Hagrid welcomed them into his hut and introduced him to his dog, Fang. A fire was going in the fireplace, and Hagrid took a tray of something called "rock cakes" out and offered them to his guests.

Phineas took a rock cake. He tapped it with his fingernail and listened to the resonation. "How exactly did you make these, sir?"

"Er..I, um..well...the fire, and some dough...wasn't _that _old, I thought..."

Ferb had already set up a laboratory analysis station. He placed a rock cake under the microscope and let his stepbrother take a look.

"Wow. It appears that even the individual atoms have been fused together," Phineas noted.

Harry saw something clipped from the newspaper on Hagrid's table. He picked it up and read the text.

"Hagrid!" Harry said. "This story is about a break-in in Gringotts, but the vault they tried to rob – vault 713 – that was the one _you _took _me _to!" Harry turned around in his chair. "Hey, Phineas!"

"_Is _it physically possible for something to be harder than a diamond?" Phineas was asking Ferb, holding up a clear gem with a prominent scratch. "Oh, yeah, Harry?"

"When I went to Gringotts," Harry recounted, showing Phineas and Ferb the newspaper clipping, "we visited _this _vault. Later, someone tried to rob it."

"What did you take out of it?" Phineas asked, reading the clipping.

Harry shook his head. "I don't know exactly. It was about two inches long, but wrapped up in cloth. What could it have been?"

Ferb shrugged. "A two-inch ruler, perhaps?"

Hagrid coughed loudly, and reached over to take the paper from Phineas. "That's none of yer business, 'Arry and Phineas. Must've been real Dark Magic te break into a Gringotts vault, so let's not get messed up in it, eh?" After that, Hagrid was almost _too _nice to them. When it was time to say good-bye, he loaded their pockets with rock cakes. Harry, Ron, and Hermione had been too polite to say no, and Ferb had wanted some samples for further laboratory analysis.

All of them were thinking that their visit to Hagrid's hut had given them more to think about than all of their classes combined.


	11. The Giant Three-Headed Dog of Doom

Madam Hooch walked between the two rows of students, Ravenclaw on one side, and Hufflepuff on the other.

"Right!" she shouted. "Now, step up to your broomstick, extend your right hand, and say, 'Up!' Got it? Sternly, but not commandingly."

"Why?" Phineas asked Madam Hooch. "Is it too much work to bend down and pick it up?"

"Of course it is!" she barked.

Phineas looked at Ferb and shrugged. He put out his hand and said, "Up!"

The room exhibited a profound lack of movement.

Phineas glanced around worriedly. Was this not working because he was a Muggle? Was this trivial fact of his birth once again preventing him from getting the complete wizarding experience? After all, when he and his brother had first approached the school, Phineas thought it looked like a dump. Fortunately, that particular spell was broken for a Muggle as soon as they managed to get into the Hogwarts grounds.

He tried again, louder. "_UP!_"

Still the broom refused to move.

Madam Hooch was looking away, so Phineas quickly bent down and just took the broomstick off the ground manually. When Hooch turned around, Phineas was leaning on his broomstick, whistling leisurely.

"Good!" she said. "Now, mount your broomsticks. We will rise three or four meters off of the ground and then land. Mount!"

Phineas and Ferb hopped onto the broom, waiting Madam Hooch's cue. She whistled loudly and made a sharp motion upwards. Ferb kicked off the ground and rose into the air.

Phineas stayed absolutely put. Everyone around him was rising into the air, but Phineas was ground bound. He tried kicking off again, but only succeeded in falling over. The Hufflepuffs laughed at him.

Madam Hooch came over. "Flynn, what's wrong? Faulty broomstick?" She took it from him and twirled it around, examining it through her goggles. "Looks fine to me. Do you have any idea why it might not be working?"

"Sure," Phineas said. "I'm actually a Muggle who stowed away in Ferb's suitcase and made a wand –"

"I get it, Flynn," Hooch said, waving a hand dismissively at him. "Sorry about the broomstick. I wonder why it doesn't work...?"

When Phineas and Ferb met Harry, Ron, and Hermione in their regular spot in the courtyard, Harry looked ready to jump in the air in jubilation.

"Guess what?" Ron asked. "Harry's going to be a new Seeker for Gryffindor! He's the youngest in a _century_!"

"Yeah," Harry said excitedly. "Neville got this Rememberall thing, but then it got stolen by Draco Malfoy, and I took it back from him on my broomstick!"

"After a _fifty_-_meter_ dive!" Ron added, jumping up and throwing his arms into the air to convey just _how big _the dive had been.

Hermione shoved Ron back on the bench. "But then Malfoy challenged Harry and Ron to a duel, and they're _not going_!" she said without room for argument.

"Where?" Phineas asked.

"In the trophy room, at midnight!" Harry told them, before Hermione shot him a nasty look.

"We've got to go to Arithmancy now," Hermione said sternly. She grabbed Harry and Ron and dragged them through the courtyard to a large set of doors.

There was a moment's silence with Phineas and Ferb.

Phineas turned to his brother. "Guess who's going to the trophy room tonight?"

_Later that night..._

Harry, Ron, and Hermione were leaning against the trophy cases, waiting for any sign of Malfoy.

"Maybe he's chickened out," Ron whispered.

"A likely possibility," a voice behind them said, and all three of them jumped in shock.

"_Malfoy_!" Harry exclaimed, brandishing his wand, ready to duel...

Phineas and Ferb poked their heads out of suits of armor. "Just us, guys. Thought it'd be fun to join in your post-bedtime shenanigans." The brothers climbed out of the armor and stood by the furious Gryffindors.

"You scared us half to _death_!" Ron reprimanded. "What with Peeves, and Filch -"

"Sniff around, my sweet, they're here somewhere," Filch, the caretaker of the castle said, and the posse of students froze.

"It's Filch!" Harry whispered in a panic, and the friends quickly ran over to another darker, further away section of the trophy room.

To their dismay, Filch was quick to follow. "Yes, naughty students, out of bed..." he told his cat. "Somewhere in this room..."

"Man, is it just me, or does this guy give _everyone _the creeps?" Phineas asked.

"Follow me!" Hermione told them, grabbing Harry and Ron's wrists, and promptly banging into a hallway full of armor.

"_RUN!" _Harry yelled, shaking a metal helmet off of his foot. Suddenly, Ron tripped, and tore down a tapestry, revealing a hidden passageway in the wall. Harry, Ron, Hermione, Phineas, and Ferb raced through it, and emerged in the Charms corridor on the third floor.

"_RUN AWAY!_" Harry encouraged, hearing the snarls of Mrs. Norris behind them. They ran through the Charms corridor all the way, but found a dead end with a locked door.

Hermione whipped out her wand. "Oh, let me! _Alohomora!_" she cast, and the door clicked unlocked. The friends ran inside to hide, slammed the door behind them, and leaned against the door, panting.

It was then that Phineas stopped panting and, very slowly, looked up from the floor. "Hey, Harry," Phineas asked casually. "If it were a choice between death and Filch, which one would you take?"

"Filch, I guess," Harry gulped, still trying to catch his breath.

"Then...why are you just standing here?"

Harry, Ron, and Hermione looked up, into three pairs of eyes all attached to a monstrous, horrific dog.

Harry made a few nervous laughs. "_MORE RUNNING AWAY_!" he screamed, yanking the door open and allowing them to exit just as the dog made a lunged forward with serrated teeth.

By the time that Harry, Ron, Hermione, Phineas, and Ferb had found refuge in a storage closet, they were scared out of their wits and gasping for air.

"Huge...dog...what...dog...doing...corridor...?" Ron asked feebly, collapsing in a corner of the closet.

"That was the forbidden corridor that Dumbledore told us about in the Start of Term feast!" Hermione told them. "Did you hear him?"

"Nah," Phineas said. "The author kind of skimmed over the feast speech."

"Did you see what it was standing on?" Hermione asked suddenly.

Ferb raised his hand. He drew a square with hinges in the air with his finger.

"Exactly!" she said. "It was standing on a trapdoor! That dog was _guarding _something, don't you see?"

"Of course!" Harry exclaimed, hitting his forehead. "Remember that grubby little package from vault 713? I think I know where it's being kept and what that three-headed dog is guarding."

Hermione, Ron, Phineas and Ferb nodded thoughtfully.

Phineas shivered. "Man, I've only seen one thing in my life scarier than that," he said.

"What was it?" Ron asked.

"Candace having an episode of her wild parsnip allergy."

Ferb shook his head. "Definitely, the giant floating baby head."


	12. Trolls and Giant Floating Baby Heads

Fall was in the air at Hogwarts. The trees were covered with orange, gold, brown and red, and the air had a definite chill in the air. Hagrid was growing giant pumpkins in his yard, which the sixth- and seventh-years loved to go out and demolish when he wasn't looking. Halloween was fast approaching, and everyone seemed overjoyed to have it come.

Phineas stared longingly out the window, sighing. His Charms class was taking _forever_, before they met up with Harry, Ron, and Hermione for the rest of the day. He rested his head on his hand and tried not to fall asleep.

"Flynn!" Professor Flitwick squeaked. "Have you been listening? We're getting our wands out and practicing the spell _Wingardium Leviosa_. Wands out, Flynn!"

Phineas slowly took his wand out. "Um...what were the words again, sir?"

"_Wingardium Leviosa_," Flitwick repeated.

After coughing politely, Phineas looked down at the ground and began bouncing his legs. "Uh...sir...could I, um...go?"

"_Another_ bathroom break?" Flitwick drawled. "Flynn, I've got to say that I've had enough with your constant needs to escape my class. Before you can go, I want to see you perform the spell."

Phineas gulped. He cast a desperate glance at Ferb, but Ferb just shrugged. Phineas was on his own for this one.

"It's an _emergency_, sir," Phineas begged.

"What, Flynn?" Flitwick asked angrily. "Go on, everyone else can do it. One quick spell, and I'll let you go, okay?"

Phineas cleared his throat. He put his wand on the desk, and whispered, _"Wand, create an area of low –"_

"Stop muttering, Flynn, and get on with it!" Flitwick yelled. "Perform the spell! Now!"

"I can't!" Phineas exploded. "I stowed away in my brother's suitcase! I can't cast magic, okay?!"

The classroom fell silent.

"Flynn, let me talk to you for a few minutes," Flitwick said sternly. He pointed Phineas to his office, gave the class an assignment, and sat down with Phineas.

"I think I know what's going on here," Flitwick said after a pause. He sighed.

Phineas panicked. Did Flitwick believe him? Were his days at Hogwarts over? Was he going to be kicked out, disgraced, as a Muggle infiltrator?

"You're MAD," Flitwick finished with a smile.

Phineas stared. "Wha –"

"It's an acronym," Flitwick said. "It stands for Magic Anxiety Disorder. You, as a Muggle-born, I assume, are _afraid_ of casting magic and being a wizard, correct?"

"Uh -"

"So your body, as a natural response, gives you an urge to go to the bathroom every time I ask you to cast a spell. You go there to recuperate and calm your nerves, before coming out and trying to use magic. It's nothing to be ashamed of," Flitwick added, patting Phineas's shoulder. "I've dealt with many students who were a MAD case. _Nothing_ to be ashamed of."

Flitwick presented Phineas with a special potion to undo the effects of his MADness. It tasted like Perry's liquidized grub and worm food at home. He accepted it with a forced smile and then raced out of the Charms classroom as fast as possible. He and Ferb didn't see their Gryffindor friends, so instead went straight down to the Halloween Feast.

"I can't believe this, Ferb," Phineas fumed, kicking a potted plant that a Hufflepuff had set down off of a balcony. "Flitwick's always talking about you – _Oh, look at Ferb, he's so advanced, he can use nonverbal spells, he doesn't need to speak to use magic_...and look at me!" he demanded. "Apparently, I'm MAD! And soon, I won't be able to use my excuse of going to the bathroom to program spells!"

The Halloween feast was incredible. Phineas and Ferb stuffed their mouths, Phineas somewhat angrily, and only remembering that he didn't have to drink all that pumpkin juice until after five goblets. He glanced at the Gryffindor table and saw the Harry and Ron were sitting without Hermione. Phineas was about to mention it to Ferb when the doors to the Great Hall burst open.

Professor Quirrel, his turban untidy and off-centered, ran across the Great Hall. "TROLL! TROLL IN THE DUNGEONS!" Quirrel flung himself in front of Headmaster Dumbledore. "Thought you ought to know," he mumbled, before sinking into a dead faint.

The Great Hall was silent for a moment.

Then, it exploded into absolute chaos.

"We're all gonna die!" a Hufflepuff first-year screamed.

"The castle's doomed!"

"Who's protecting our commons rooms!?"

"_My watermelon_!"

Dumbledore immediately stood up. "Heads of Houses! Take your students to their dormitories! Food will be sent up to them, but please hurry!"

Phineas and Ferb were following the Ravenclaw Head Boy and Girl, but then they saw Harry and Ron sneak off by themselves.

"Maybe Hermione's in trouble!" Phineas exclaimed. He snapped his fingers and shook Ferb by his shoulders. "Ferb, I know what we're going to do today! We're going to save Hermione Granger from a troll on Halloween night!"

The two brothers ran through the hall until they met up with Harry and Ron.

"Hey, guys, what are you doing here?" Phineas asked.

Ron snorted. "Could ask _you _two the same question."

"Well, actually," Phineas began, "you could ask me any question at any time you wanted, but only in a situation such as this is it logical and applicable. We're following you two to help with the troll."

"Hermione is such an idiot!" Ron exploded. "In the bathroom, crying all day...seriously!"

"Against the wall!" Harry suddenly shouted, pushing them all into a doorway. "And be really quiet!"

Then, they saw the troll. Twelve feet tall, with ugly gray skin, that sagged around it, and the smell emanating from it was incredible. The troll was dragging a club, which was making deep gouges in the castle floor as the troll walked. The troll sniffed for a moment, and Phineas feared that it might smell them. But instead, the troll looked into another doorway at the end of the hall and wandered inside.

"Let's lock it in!" Harry said. He and his friends raced to the door, made sure the troll was inside, and bolted it shut.

"Yes!" Ron shouted. "Fifty points to Gryffindor for trapping the troll!"

There was a sudden, high-pitched, petrifying scream.

Harry, Ron, Phineas and Ferb paled.

"Don't tell me we just locked the troll in the girls' bathroom," Harry said desperately.

Phineas jerked the door open, and they ran inside. Just a few steps inside, all of them froze.

The troll, twice as tall as any of them, glared down at them with a tiny brain but enormous claws and club. Hermione was trying to hide under a sink, but it was obvious that the troll knew she was there.

The troll let out with a humongous roar, and swung its club at Harry, Ron, Phineas and Ferb. The friends gave a yelp and jumped out of the way, but the troll tried with another swing. After missing again, it turned its back on them and prepared to strike at Hermione.

Harry then did something very brave and also very stupid. With a running jump, he leaped onto the troll's back and accidentally stuck his wand up the troll's nose. The troll bellowed and tried to grab Harry.

"Don't worry, Harry! I've got an idea! I'll save you all!" Ron shouted, waving his wand in a grand manner, obviously pleased to be the one to save the famous Harry Potter. He cleared his throat and said, "_Wingardium Le_ – _oof_!" The troll had swung his club and hit Ron, who collapsed in a ginger heap on the bathroom floor.

"It's up to us, Ferb!" Phineas shouted, getting his mechanical wand out. "Hey, ugly!" he shouted up at the troll.

The troll stopped and stared dumbly at Phineas.

"Yeah, you! Think you're so _scary_? It's Halloween, ugly! So bring on the scary – and I mean _really _scary!" Phineas waved his wand, and willed the image of the scariest thing Ferb had ever seen into existence.

A giant floating baby head materialized in the air in front of the troll.

The troll roared in horror and backed away, scrambling to get away from the scaring image. The giant floating baby head drifted closer, and closer, and closer...

The troll pressed itself into a corner, shielding its eyes, howling in terror. It writhed and screamed and made very loud banging noises, trying to escape...

"What? What?" Ron exclaimed, jumping up out of his faint suddenly. "Uh...uh _Wingardium Leviosa!_"

The troll was lifted into the air like it was sprinkled with Tinker Bell's pixie dust. Then, it fell, crashing to the floor, but not stopping there. The troll _BURST_ through the ground, creating a giant hole in the bathroom floor, and fell with a splash into the lake below the castle.

With a _bang _the bathroom door opened, and McGonagall, Dumbledore, Quirrel, Snape, Flitwick, and Sprout all ran into the room, brandishing their wands. Then, they saw the hole in the floor and the apparent lack of big scary troll

"Er...um...where's the troll?" Flitwick asked curiously, scratching his head with his wand.

Ferb pointed with a finger, which the teachers followed simultaneously to the hole in the floor. All of them jumped back in shock.

"What?" McGonagall demanded, stepping forward to peer into the conspicuous hole. "But...but..._how_?" She glared at Harry, Ron, and Hermione. "Do you have an explanation for this?"

Hermione stepped forward. "It was my fault, Professor. I...I thought I could take the troll myself. Harry and Ron just came to save me."

McGonagall looked down at her. "Five points from Gryffindor, Granger. But five each for you, Mr. Potter and Weasley. Few students have managed to take on a troll and lived."

"_Hem-hem_," Phineas said rather loudly.

"Ten points to Ravenclaw!" Flitwick squeaked happily. "Excellent jobs, Fletcher and Flynn! A very creative use of a giant floating baby head!"

"A _what_?" Snape asked, crossing his arms.

"A giant floating baby head," Phineas repeated.

Snape snarled and turned around, swishing his cloak dramatically. "Honestly, Potter, and Flynn and Fletcher, I'm not sure which of you has screwed this school up the most," he snapped, the words dripping poison.

The students and teachers watched Snape stalk away.

Ferb blinked. "Probably Flynn and Fletcher."


	13. Another Brief Interlude with Dr D

"Okay, Norm," Dr. Doofenshmirtz said, fitting a seat onto his giant robot's back. "Listen closely. You are going to fly me very high _over _that lake, and set me down somewhere by that run-down old castle."

"Is this your vacation home?" Norm asked happily.

"No!" Doofenshmirtz clambered onto Norm's back. "Now, go! Go, fly, away!"

Norm lifted off from the ground in a cloud of smoke, like a rocket taking off. He drew an arch in the sky, flying above Hogwarts Lake in the chill breeze.

"Should I serve refreshments on this flight?" Norm asked.

"No! Just fly, for Pete's sake."

"But it's Muffin Time, sir!"

"Oh, you're broken!" Doofenshmirtz snapped. "Concentrate on _flying,_ Norm."

Suddenly, Norm's engine gave a pathetic little sputter and then died out completely. Norm began to fall towards the dark lake.

"Uh-oh! Looks like someone forgot that technology doesn't work near Hogwarts!" Norm said, as gravity dragged them downwards.

"Oh, no, not _again_!" Doofenshmirtz yelled, as the giant squid of Hogwarts Lake picked him and his robot into the air, wrapping its tentacles around both.

"I just love calamari!" Norm exclaimed.

Unexpectedly, the squid reached a third tentacle into the water and withdrew a mountain troll. Doofenshmirtz yelped and tried to escape, but the next second, the giant squid had hurled all three of them back to the shore, where they crashed in another grove of trees.

"CURSE YOU, CARRIE THE CEPHALOPOD!" Doctor Doofenshmirtz screamed, thrashing about in the tree branches.

The only part visible of Norm was his metallic legs.

"Look at me! I'm connecting with nature!"

"Oh, shut up," Doofenshmirtz commanded, rolling his eyes.


	14. Clubhouses and Christmas Presents

A/N: I don't own Phineas and Ferb or Harry Potter. By the way, if you read my reviews, two of them (so far) call me Canada or Canadia, and are from 'Italy', an...ah..._energetic _friend. A group of friends and I assigned countries to ourselves, and I'm Canada. If you don't know what Hetalia is, look it up this instant, because everything will be explained.

Also, this chapter is a bit of a long one, but Phineas gets a very important Christmas present in here that he'll be using throughout this entire 'series' of mine. Yes, I'm planning on writing the whole series. Now I've said it, so you can all hold me accountable for it and I've got to make a commitment.

Sorry I haven't been updating my chapters for a while, but I've been super busy. To make up for the delay, and since I won't update all through the winter holidays, I have a BO-AT full of new chapters for you guys to read! Enjoy and review! Thanks for tolerating the long A/N.

Harry, Ron, and Hermione's feet left faint footprints in the dusting of snow. It was the day before Christmas, but Hermione was anything but merry.

She had been quiet for most of the walk, but finally exploded and turned to her friends. "Ask me!" she demanded, standing in front of them. "Ask me _where _I found Nicholas Flamel's name mentioned! Go on," she fumed.

Harry looked over his shoulder. "Er...where?"

"NOWHERE!" Hermione exploded again, turning away from her friends. "NOWHERE! I checked in just about _every _single book in the library! _A Study of Recent Developments in Wizarding History_, _Great Wizards of the Twentieth Century, Great Wizarding Events of the Twentieth Century, _and NOTHING!"

Hermione suddenly stopped. She looked up.

"What are they doing?!" she shrieked, and ran for the castle.

Ron looked up as well. "Bloody hell..."

Harry followed their gazes. He gasped.

Phineas and Ferb were on top of the Ravenclaw tower, but _they_ weren't the surprising element. A gigantic house made of gingerbread, with a candy cane chimney, and large neon signs in which glasses of milk were downed and proclaimed, "_WELCOME, SANTA!"_

Harry, Ron, and Hermione raced to the top of the stairs and emerged on the Ravenclaw tower roof, huffing and puffing for air. They managed to stumble over to Phineas, who was directing a few Ravenclaws with a support beam.

"Phineas...Ferb...what _is _this?" Hermione asked them, her mouth gaping and pointing at the structure.

"Take a guess," Phineas encouraged them.

"Erm...a clubhouse?" Harry asked tentatively.

Phineas's gaze bore into him. "No. It's _not _a clubhouse. This is a perfectly tailored rest and relaxation stop for the jolly red-suited world traveler himself for his journey tonight."

The three Gryffindors had blank expressions.

"It's a rest stop for Santa," Phineas recapped.

Hermione laughed, loudly enough to stop the workers' progress and stare.

"Santa? You're not _serious_, Phineas? That's for Muggles! And _toddler _Muggles!" She covered her mouth in an attempt to stop the laughter, but it simply continued. "What, are you going to help _feed his reindeer_ when they get here? Are _North Pole elves_ here to help you with construction? Are you –?"

A tiny man with a beard and a green suit came up to Phineas. "Phineas, which outlet should the beard purifier be plugged into?"

"I'm thinking, Clewn't, the one to the left of the sauna," Phineas told him, gesturing over to the house.

"Right-o." He turned to Hermione and squinted his eyes menacingly. "I'll ignore those statements for now, Granger, but _I'm watching you_." With an "I'm watching you" motion with his two fingers, Clewn't went to plug in the beard purifier.

Phineas gave a smiling, knowledgeable look to Ferb. "And this is why Hermione is _not _a Ravenclaw."

"_FLYNN! FLETCHER!_"

Phineas wheeled around, just in time to see Snape, the Potions Master, staggering up the staircase, trying to catch his breath.

"What sort of...of vile _monstrosity_ are you constructing on the roof of this noble building?!" he demanded.

"Whoa, whoa, _whoa_!" Phineas said, holding up his hands, looking annoyed. "This is no quote-un-quote, '_vile monstrosity'_. This is a rest stop for the greatest gift-giving world traveler in...well, history. We've included –"

"No matter!" Snape spat. "I demand you tear down this clubhouse _immediately_!"

There was a prominent silence above Ravenclaw tower.

Phineas buried his face in his hand. "The price of architectural genius..."

"Look, I don't _care _what it is," Snape said, his words as oily as his hair. "Just take it down. _Now._"

"But it's a rest stop for Santa!" Phineas whined. Ferb held up an autographed picture to accentuate his point.

At this point Snape began laughing. "What, that stupid Muggle children's tale? How _pathetic_," he said, sneering at the stepbrothers. "Is he going to teach you _toy making_? Have you stocked up on _milk and cookies_? Are there _magical elves _here to help with –?"

"That's it!" Clewn't snapped, stepping in front of Snape with Blay'n. "You're not getting _any _presents this year!"

Blay'n scoffed. "As if he was going to get presents _anyway_." They lifted their noses and carried a tray of nails to some Ravenclaws in charge of hammering.

Snape's face puckered up, like he had just popped a huge slice of lemon into his mouth. Then it became a bitter grimace.

"Detention," he sputtered, turning around to walk down the stairs. "Detention for both of you, Flynn and Fletcher. The night after Christmas. My office." He harrumphed and started down the stairs.

Harry, Ron, and Hermione looked to the brothers to see their reaction, as did everyone on the Ravenclaw tower roof.

Phineas shrugged and smiled. "I'd take detention any time over not giving Santa Claus a place to relax and rest between runs. Let's get to work, Ferb!" He looked over at the Gryffindors. "Wanna give us a hand?"

Harry, Ron, and Hermione spent the rest of the day putting up gingerbread walls, installing reindeer feeding stations, and putting together elliptical machines. They washed all the work down with substantial milk and cookies, and by that evening Santa's rest stop had been completed.

The sun was setting in a brilliant array of purple and gold, low enough in the sky that it looked like it was perched on the tower railing. Hermione, Ron, and Harry were trudging to the staircase when Phineas called them back.

"Guys! Wanna stay here and wait up for Santa?"

Hermione and Ron looked back at the completed gingerbread masterpiece. They shook their heads.

"Sorry, mates, I'm dead," Ron told them, with a huge yawn. "Have fun, see you tomorrow."

"I'm still, overall, dubious of Santa Claus existing," Hermione sniffed. "Those elves could easily have been house elves you paid to work for you. It's unfair; if I said it once, I've said it a thousand times. They're not really from the North Pole..."

"_Granger_!" Clewn't yelled from the gingerbread house.

Hermione jumped in fright and grabbed Ron by the shirt, scurrying down the stairs like a frightened rabbit with a carrot.

Harry looked to the staircase. "Er...well, I'm not sure..." He scratched the back of his neck.

"It'll be fun," Phineas promised. He and Ferb gestured questioningly at the gingerbread house.

Harry sighed, and turned around. "Well, okay. I guess."

They were waiting at the clubhouse that night, when Phineas heard bells jingling outside.

"Santa!" Phineas exclaimed, and rushed out the door with Ferb. On the parking space/runway there was a sleigh with nine reindeer harnessed to it. Someone in a red suit was bent over a bag of toys next to the sleigh. When Phineas said his name, he turned around.

"Phineas! Ferb!" Santa laughed, setting down the bag of toys. "Good to see you boys again. I see you got my...uh... message about the global warming."

Ferb nodded, and poked his thumb behind him at the gingerbread house. "Make sure you put _this _one on thicker ice."

Santa leaned to his right to look past Phineas and Ferb. "Come on out, Harry. Don't be shy."

"Oh, Santa," Phineas said, yanking Harry out of the house. "This is our new wizard friend, Harry Potter. Harry, meet Santa Claus."

Harry adjusted his glasses awkwardly. "Er...hello, sir..."

"Pleased to meet you," Santa said, shaking his hand. He laughed again. "Now, who wants presents?"

Santa heaved his sack of toys off of the sleigh. "All right...I've got some _very _special presents for you three this year," he told them, smiling. "Let's see...ah..._here _we are!"

Turning around to face Harry, Santa presented him with a small packaged box. "Merry Christmas, Harry Potter."

Harry undid the ribbon and lifted the lid. His eyes widened as he pulled out a silky, black cloak. He held it up to the moonlight and pushed his glasses further up his nose. "Thanks, sir. It's a very nice cloak."

Santa chuckled knowingly. "Try it on, Harry. I'm not one to hand-deliver presents as simple as that."

Harry smiled nervously and pulled the cloak on over his shoulders.

Phineas and Ferb stared. "Uh, Harry..." Phineas began.

Ferb held up a mirror.

Harry gasped as he saw he was only a floating head. "It's the cloak!" he exclaimed. He pulled it over his head as well, and even though he could see through it, the reflection in the mirror showed he had disappeared completely.

"Yes," Santa chuckled again. "An _invisibility _cloak."

Harry pulled off the cloak, grinning broadly. "It's...it's _great_, sir...thanks, a lot!"

"Now, let's move on to _you_, Ferb Fletcher," Santa said, reaching into his pack. He pulled out an even bigger package and handed it to Ferb.

Ferb lifted the lid and pulled out a set of harmonicas, each in a different key. He gave a thumbs-up to Santa Claus.

"I think you know what they're for," Santa said, winking at Ferb. He cleared his throat and turned to Phineas. "Now, Mr. Flynn. Here." He held out a package, which Phineas took slowly.

"Before you open it, there's something you and Harry Potter should know," Santa said. Harry and Phineas stood side by side and listened.

"Both of your presents came from someone _very special_ –"

"Yes, sir, you," Harry finished for him.

Santa shook his head. "No, not me. I'm just delivering. These things I'm giving you used to be your fathers'."

Harry and Phineas were struck dumb. They stood with their mouths open. Phineas looked down in wonder at his package. With a slow, trembling hand, he lifted up the lid.

Phineas pulled out what looked like a handheld gun, something obviously Muggle-made. He turned it over in his hands and read writing on the side:

_RANDOM-THING FLINGER _

There were four or five more letters after the last word, but they were crossed out with a black marker. Phineas tried to rub the marker off, but the marks seemed permanent.

"I'm sorry, Phineas," Santa told him. "But if you could read those letters, you would know who your father was. The giver of the gift requested I not let you know yet."

"What does it..._do?"_ Phineas asked, examining it more.

"Well, firstly, it needs to charge. An outlet, or your wand, will suffice. But I've already done that for you."

"But my wand is mechanical," Phineas protested. "And it won't work in Hogwarts."

Santa shrugged. "It won't make a difference. The machine is specially designed to work with magic."

"So my father _couldn't _have been a Muggle pharmacist," Phineas said. "Because he knew about magic..."

"Why not give it a try?" Santa suggested.

Phineas pointed the Random Thing Flinger down Santa's runway and pulled the trigger.

There was a blinding flash of light, and suddenly, a giant petit four exploded from the Random Thing Flinger. It shot through the air like it had been launched from a cannon and smashed into a gargoyle on the side of the castle.

Phineas smiled. "Sweet" he exclaimed. "Ferb, did you – Ferb?"

The gingerbread house was sitting in the back of Santa's sleigh, and Ferb was just finishing tying the knots to hold it in place. He gave the thumbs-up to Santa. "Ready to go."

"Thanks, Ferb," Santa said. He climbed into the driver's seat and waved to the three boys. "Hyaa! On Dasher, on Dancer, on Prancer and Vixen! Merry Christmas, Phineas and Ferb, and Harry Potter! HO HO HO!"

He waved to them as his reindeer took off, and his sleigh became a tiny red dot in the black sky.

"Some presents we got, huh, bro?" Phineas asked Ferb, laughing. "Wow, the Random Thing Flinger from my very own dad..."

"Some presents we sent, too," Ferb answered, waving at Santa.

Harry stopped waving and looked over at them. "What? Who did you send presents too?"

"Our sister, Candace. We sent Perry out with her gift." Phineas laughed and looked at his stepbrother. "Hope she really feels _attached _to her present his year..."


	15. Candace Flynn's Christmas Present!

A/N: I don't own Phineas, Ferb, or Harry Potter. Candace will kind of be 'forgotten' for most of the book from here on, but makes a big reappearance near the end. I've got big plans for Candace and the Panic Room!

"I _know_, Stacy!" Candace said, pacing back and forth in front of the window. "It's so_ quiet _without those little dweebs around! Yeah, uh-huh, I _know _they're my brothers, but it's nice not having to worry about busting them. What? Of _course _I miss them, Stace! I miss busting their little..."

Candace happened to look down just then, and noticed something very odd.

"Uh, Stace? I'm gonna have to call you back...okay? Bye." Candace hung up the phone and opened the kitchen screen door.

She blinked. "Perry? What are _you _doing here, you little meat brick? I thought that Ferb took you with him for a pet."

Perry shook part of the Atlantic Ocean off of him and set down a Christmas package at her feet. He made his platypus chittering noise and hopped out the screen door.

Candace watched him disappear behind the house, but then shrugged and closed the door. She picked up the package and set it down on the kitchen table.

It didn't do anything.

She narrowed her eyes, obviously suspicious. When one is the sister of Phineas and Ferb, though, one has ample reason to be suspicious. Candace shook the present and listened carefully.

Nothing happened.

Candace put the present down again and lifted the lid. When she saw the present inside, she scoffed, and brought out a tiny little potted plant. It was barely a foot tall, including the pot it was in, and had long, vine-like leaves. "Really, you nerds?" she laughed. "This is _way _below your usual standard." She laughed again and poked one of the leaves.

The Devil's Snare convulsed and then snapped its tentacles around Candace's hand.

"_AAAAAAAAAAAAAAAAAHHHHHHHHHHH HHHHHHHHHHHH!"_

Candace ran around the house, shaking her hand as violently as possible. "_AAAAAAAAAHHHHH GET IT OFF GET IT OFF GET IT OFF GET IT OFF GET IT OFF!"_

Candace continued screaming shrilly, breaking every window in the house. She rushed into the garage and fumbled with the Weed-B-Gone, before dumping the whole canister on the thing.

It did not relinquish its grip.

"_AAAAAAAAAAAAAAAAAHHHHHHHHHHH HHHHHHHHHHHH!"_

She ran to the shed, wild with fear, and grabbed Ferb's spare blowtorch. She set it on EXTRA-HIGH and let the plant have it.

It did not let go.

"_AAAAAAAAAAAAAAAAAAAAAAAHHHHH HHHHHHHHHHHHHHHHHHH!_"

Candace tried everything: She dunked it boiling oil, screamed; exposed it to extreme gamma radiation, screamed even longer; she forced it to watch long episodes of clichéd childrens' television shows, and screamed the longest.

Nothing she did affected the plant in the least.

Candace screamed again, and ran back inside the house, throwing the basement door open. She raced down the stairs, found a wooden crate in a dark corner, opened it, climbed down the ladder inside, and called her mother.

"_Mommy?_" she asked tentatively into the phone. "_I'm in the Panic Room." _

Linda Flynn, looking at deli meat at the grocery store, sighed. "How did Phineas and Ferb do something when they're in a different country?"

Candace began sobbing. "MOM! They sent me a plant, and it wrapped around my hand, and I can't get it off, and I want it off and Phineas and Ferb are so busted and_ MOMMY! Get it off_!"

"Candace, honey," Linda told her, looking back at the angry line behind her. "You're a big girl. You can do this! Okay, I'm going to hang up now. Bye, Candace!"

In the steel-plated, cold Panic Room, holding onto Mr. Miggins the bear, Candace shut her phone and began sobbing again.

"_GET IT OFF GET IT OFF GET IT OFF GET IT OFF GET IT OFF GET IT OFF!_" she screamed, running around the Panic Room hysterically. She ran to a steel wall and began banging the plant against the wall to every word. "_GET! IT! OFF! GET! IT! OFF! GET! IT! OFF!_ _GET! IT!_ – "

Suddenly, the wall made a loud creaking noise, groaned, and fell over.

Candace screamed again and covered her head, as an explosion of dust and dirt filled the air. She coughed, and waited for the dust to clear.

The steel wall of the Panic Room had fallen over, revealing a tunnel through the earth. It loomed before her, dark and foreboding.

Candace shook her head. "Okay, okay, I just need to get back up and tell Mom. Those boys are SO BUST-"

Candace had put one foot down on the ladder, and it had snapped in half.

"So busted. Ha. Funny!" she shouted at the sky. Candace glanced down the dark tunnel again and whimpered.

"Meep."


	16. Detention and the Mirror of Erised

"Well, well, well. Flynn and Fletcher."

Phineas and Ferb, who had been discussing just _where _giant floating baby heads came from, stopped short. Towering over them was Snape, the Potions Master.

"Looks like we've forgotten about our detention, hmm?" he asked, grinning evilly. He crossed his arms.

"But...it's only noon," Phineas pointed out.

"I don't care," Snape said. He turned around, swishing his cloak. "Come with me. Fifteen points from Ravenclaw for being late."

Phineas and Ferb, though fuming at Snape, followed him through the hall of Hogwarts and down into the dungeon where Potions classes were.

"You'll begin by cleaning out cauldrons," Snape instructed, gesturing at a stack of dirty cauldrons against the wall. "Next, you'll be filling these jars with bat spleens. Every one you spill on the floor will cost ten points to Ravenclaw _each_. When you've finished with that, come and see me, and I'll think of something else unpleasant to do. And _no magic_," he added, before taking out his Great Big Book of Detentions and beginning to write.

Phineas and Ferb took to scrubbing cauldrons clean. The pile was so big that it seemed it would take all night just to finish that task.

"Man, Ferb, my arms are _killing _me," Phineas complained, starting his ninth cauldron.

Ferb put a hand on his shoulder to comfort, and then went back to his sixty-fourth.

The sun had been down for a few hours, and it was the dead of night when something exciting happened. Phineas and Ferb had begun to package bat spleens when the Potions door burst open and Filch came running through.

"Severus!" Filch rasped. "There's someone in the Restricted Section; you said to come to you if I found anyone there!"

Snape emerged from his office. "What?" He made a growling noise in his throat and looked back at Phineas and Ferb.

"You'll be finishing your detention tomorrow night as well!" he snapped. "Now get to your commons." He shoved them out the door and began running down the corridor, following Filch.

"Wonder why Snape's so concerned that somebody's in the Restricted Section?" Phineas asked. He smiled and looked over at Ferb. "Ferb, I know what we're gonna do tonight!"

Phineas and Ferb slinked through the hallways of Hogwarts on tiptoes, listening for any noise. They snuck up to the library door and Phineas yanked on the handle.

"Locked!" he said. "Bummer." Phineas took out his wand and cast, "_Alohomora_!"

"_Please insert the key_," the library door chirped.

"Agh, it's been Alohomora-proofed," Phineas sighed.

Ferb held up a finger. He took out one of his harmonicas from Christmas.

_"Please insert the key_," the door said again.

Ferb put the harmonica to his lips and played a single note.

There was a moment's silence.

"_That'll do_," the door said, and swung inwards.

"Cool!" Phineas exclaimed happily, and the two stepbrothers crept into the library. Almost immediately, they saw Filch and Snape with a lantern.

Phineas and Ferb pressed themselves into a doorway to avoid being seen.

"I wonder what Snape is up to?" Phineas asked his brother. "It seems like this whole time he's been hiding something, you know?"

Ferb poked Phineas on his shoulder.

"What is it, bro?" Phineas asked. Ferb pushed the door behind them open and pointed inside. Phineas peeked into the room and gasped.

"Harry?"

Harry was sitting in front of a large, gold-framed mirror, smiling. He didn't seem to hear them.

"Harry!" Phineas exclaimed again, he and Ferb entering the rather small room. It looked like a disused classroom, with desks piled up against the walls and upturned chairs.

Harry seemed to snap out of his stupor. "Phineas? Ferb? What're you doing here?"

"We were just following Snape around," Phineas said, coming up to Harry.

"It's great you guys are here!" Harry almost shouted. He steered Phineas over to the mirror. "Look at this! You can see my whole family in here! Just take a look!"

Phineas stood in front of the mirror. It was a big thing, with clawed, gold feet and some kind of writing on the top.

"Ferb!" Harry shouted suddenly. "Come here and see this! It's my entire family, right in this mirror!" He took Ferb by the shoulders and put him in front of the mirror.

Ferb watched the mirror for a few moments. He smiled, and waved once, and then left the mirror for Phineas to see.

Phineas's eyes were fixed on the mirror. He walked slowly, almost trancelike, up to the mirror and pressed his face against it.

"Do you see them?" Harry asked eagerly. "Do you?"

"Well, no," Phineas admitted. He kept staring into the mirror. "What does this Mirror do? Does it show your true self?"

Harry shook his head. "No idea." He came and stood by Phineas, and together, they spent quite a long time staring into it, lost in a world all their own.

"_Hem hem_," a polite cough came from behind.

Phineas and Harry spun around, hearts racing, thinking of Filch and Snape, but it was only Professor Dumbledore.

Dumbledore smiled behind his half-moon glasses. "Good evening, Harry, Phineas," he said, slowly walking to them. "I see that you, like many before you, have discovered the delights of the Mirror of Erised."

"Is that what it's called?" Harry asked

Dumbledore nodded solemnly. "Yes. Do you know what it does?"

"Does it show your true self?" Phineas asked hopefully.

"In a sense," Dumbledore answered vaguely. "Here is a clue – a man who is completely happy with himself and his life could use this as a regular mirror."

Phineas glanced back at the mirror, disappointed. "So it just shows what you want?"

"Oh, not just what you want." Dumbledore stood in front of the mirror, and an almost aching look came into his eyes. "It shows nothing less than your heart's deepest, greatest desire."

"But, boys," Dumbledore continued. "A warning. Men have wasted away in front of this mirror, entranced by what they want but cannot have. No one can resist his deepest desire placed right in front of him –"

As he said it, everyone looked behind them at the same time and saw Ferb sitting patiently in a corner, reading _War and Peace_. He caught them looking at him and waved.

"Well, _most _people could not resist his or her greatest desire placed in front of them," Dumbledore admitted. "Your stepbrother continues to amaze me, Phineas."

"Sir?" Harry asked timidly.

Dumbledore adjusted his glasses. "Yes, Harry?"

"What do _you _see, when you look in the mirror?"

Dumbledore seemed to hesitate for a moment. "Me?" he answered at length. "I see myself holding a pair of thick, woolen socks. I never get enough socks for Christmas. People always insist upon giving me books."

"Now," Dumbledore said, and he waved his wand so that a blanket fell over the mirror. "I suggest you go back to your commons and get some sleep. Do not try and look for the Mirror of Erised again – it will be moved to a dangerous location in a short while, one that I hope you do not try to breach."

Ferb closed his book and stood up. He gave a thumbs-up to Dumbledore, and he, Phineas, and Harry all filed out of the room.


	17. Doofenshmirtz's M-OTOR-BOAT

A/N: I do not own Harry Potter or Phineas and Ferb. However, I do take full credit for the Monotreme Operated Totally Aquatic Revamped part of M-OTOR-BO-AT. Thank you very much.

The sky was just being lit up with the early morning's light. Aberforth, the owner of the Hog's Head Tavern, was just putting out his cat when he witnessed a teal-colored, semi-aquatic, egg-laying mammal coming up the street.

His mouth opened in an unasked question, and he watched the platypus waddle up the street and turn the corner that led to the Hogwarts Castle.

Once he turned the corner, Perry the Platypus backed up against the wall and put on his fedora.

_He _had become Agent P.

Perry ran through the forest and onto the shore of Hogwarts Lake. He stopped on the beach, looking at the castle across the water. Perry took a deep breath and prepared to dive into the lake.

Before he could do that, however, a metal cage sprung up around him.

Doctor Doofenshmirtz ran out from behind a tree. "Finally! Finally, I have captured one!" he shouted, delighted. "Now, I will use this platypus to power my machine and finally take me across..."

His voice trailed off as he saw what _specific _platypus he had captured in his cage.

"Oh! Oh, look at this! Ah, Perry the Platypus," Doofenshmirtz cackled, rubbing his hands together. "What a _surprise. _Your timing is astonishing. And by astonishing, I mean, _completely tonishing_!"

Perry stared. He blinked.

"Okay, so that doesn't really work," Doofenshmirtz admitted sheepishly. "Whatever. But the main thing is, _you're here_!" He paced back and forth in front of his nemesis, overjoyed at his good luck. "The _irony _of the situation is that I wasn't even _trying _to capture you! I was just hoping for an ordinary platypus!"

Doofenshmirtz took a remote control out of his pocket. "Behold...The Monotreme Operated Totally Organic Revamped Buoyancy Operated Aquatic Transport!"

"That's M-OTOR-BO-AT, for short."

Perry blinked and stared again, for even longer.

"Yes, you see, Norm was squirrel-operated, it was true, but the squirrel, unfortunately, produced an electric current, which failed as soon as we came near this castle thing," Doctor Doofenshmirtz said. "So I found the scattered remains of my BO-AT, and reassembled them so that a running platypus could turn these paddles and make my machine go!"

"What's more," Doofenshmirtz said, with an evil grin, "is that, with _you _on board running it, Carrie the Cephalopod will be _forced _to let me cross! He wouldn't _dare _harm another secret agent – I think it's in your manual, somewhere. Besides, he can't help thwart you if _you're _in the middle of thwarting _me._"

Doctor Doofenshmirtz carried Perry's cage to his M-OTOR-BO-AT. He put Perry in to an oversized hamster wheel. Doofenshmirtz sat in front and held a fishing pole with a worm on the end.

"Platypuses eat worms, right?" he asked, unsure. "I mean, at first I used fish, but I saw, like, twenty platypuses sniff it and pass by."

"Anyways," Doofenshmirtz said, sitting in the front seat, and holding the fishing pole out in front of Perry. "MUSH!"

Perry rolled his eyes and stayed perfectly still.

Doofenshmirtz glared at Perry. "What? All I want to do is go to that island so that I can find you and make you foil my plot. Let's _go,_ Perry the Platypus!"

Perry crossed his arms and made his platypus chittering noise.

"Party pooper!" Doofenshmirtz yelled. He dangled the worm in front of Perry's hamster wheel. "Don't you want it? Are you not hungry or are you just being a _jerk_?"

Perry checked his watch, and glanced idly at Hogwarts Castle. He sighed.

Suddenly, the M-OTOR-BO-AT began to slide through the water.

"Yes!" Doofenshmirtz yelled into the wind. "It is working! Perry the Platypus is taking me to the castle so that I can capture Perry the Platypus and make him foil my plot!"

He stopped.

Doof put a finger to his chin. "Wait, if you're already here...why am I still going to the castle?"

Doofenshmirtz honked the M-OTOR-BO-AT horn. "Perry the Platypus, stop! I changed my mind! Let's go back! I don't need to go here!" He honked the horn again. "Perry the Platypus, stop! UNMUSH!"

Perry sighed again. He kept running the wheel, even as Doctor Doofenshmirtz yelled, screamed, and honked the horn at him. Perry let him make all the noise he wanted. The giant squid wasn't the only thing in Hogwarts Lake.

With a savage cry, a troop of merpeople leapt out of the lake, angered by the noise of the M-OTOR-BO-AT. They sank their spears into the sides of the M-OTOR-BO-AT, letting the water gush in. Doofenshmirtz shrieked and tried to bat them away with his Duct-Tape Inator.

"NO! Shoo! Away, strange, fish, hybrid, man..._things_!"

The merpeople saw Perry in his cage. Perry looked at them with pleading eyes and made his distinctive platypus chitter.

Merpeople, of course, have a natural soft spot for most anything aquatic. Three of them, swimming near Perry's cage, recognized him as a semi-aquatic mammal, and made a sympathetic gurgling noise. They took their spears and pried the hamster wheel in half, letting Perry swim off, free.

Doofenshmirtz saw Perry escaping from his cage and swimming from the castle. "Perry the Platypus!" he screamed. "I'm not through with you yet! You'll foil my plot, if _it's the last thing you do!"_

Pinkish tentacles slithered through the water to his M-OTOR-BO-AT, and even the merpeople stayed near the surface to watch the fun.

Doofenshmirtz sighed. "Curse you, Perry the Platypus, blah blah blah," he said without much heart. He looked over at Carrie the Cephalopod's tentacles. "And here we go _again_..."


	18. Phineas 'Loses' his MAD Medicine

A/N: I don't own Harry Potter or Phineas and Ferb. Read and review!

Hermione paced back and forth in front of Harry, Ron, Ferb, and Phineas. The latter four were sitting on a bench in the courtyard, where they all liked to meet.

"So, let me get this _straight_," Hermione told them, frustration building up in her voice. "Not only did you break at least _seven_ school rules, but you almost got caught by Filch, Snape, and located an _extremely _dangerous, possibly _Dark _object?"

"Actually, you forgot to mention that we didn't even find out anything about Nicholas Flamel," Phineas pointed out happily.

"Exactly!" she shouted. "And you _didn't even _find out _anything _about Nicholas Flamel! What a _waste of time_!"

Phineas coughed politely. "Well, now that you've spent forty-five minutes chewing us out, can we please get to class? I have Charms next."

"What Ho!"

Phineas, Ferb, Harry, Ron, and Hermione jumped in surprise. They all whirled around, and saw a ghostly knight upon his ghostly horse. He had an exuberant mustache and waved his hand grandly at them.

"Noble Sirs and Gentle Lady, I bid you a good morn!" he said loudly, giving them a gracious bow from his horse, and nearly falling over in the process.

"Hi, Sir Cadogan!" Phineas greeted. "Harry, Hermione, Ron, this is Sir Cadogan. He heard about our jousting competition this summer and was _really_ impressed."

"'Tis well to see young wizards respecting my noble age!" Sir Cadogan said, swelling importantly.

Phineas smiled to the Gryffindors. Aside to them, he said, "And yes, he speaks like this _all _the time."

"I heard that you're bound for the Charms corridor!" Sir Cadogan said. "Shall we be off on this grand adventure?"

"Sure!" Phineas said eagerly. He and Ferb hopped off of the bench, and waved goodbye to their Gryffindor friends.

"Good morn, Friar!" Sir Cadogan called as they passed a rather plump ghost. "What cheer?"

"Oh, horrible news," the Fat Friar said, and floated next to them. "They saw that Severus Snape is going to referee the next Gryffindor Quidditch match, against Slytherin."

"I say!" Sir Cadogan exclaimed. "Do you remember the outcome of last match against those Houses?"

The Fat Friar nodded. "Indeed, I do. Poor Harry Potter was nearly knocked off of his broom – some say it was _jinxed_. How disgraceful!"

Phineas and Ferb had reached the Charms classroom, so they left their ghostly company and prepared to endure another lesson.

"Good morning, Phineas!" Filius Flitwick called to him. "How's that potion working?"

Phineas laughed nervously. "It's...okay, I guess..."

"Good, good," Flitwick said. "Take your seats!"

It was another tortuous Charms class. Flitwick had high hopes for Phineas, now that he'd been taking the MAD potion for a few weeks. Phineas had been trying to program spells into his wand as fast as possible, but science and magic were two different things. It was relatively easy to tell the wand to produce water, but levitation and setting things on fire were completely different. How did you scientifically make something rise up into the air? To Flitwick's disappointment, Phineas was still not able to perform most of the spells they were learning.

After class, Flitwick called Phineas back into his office. Phineas sat in a corner chair, dreading the talk.

Flitwick sat at his desk, across from Phineas. He sighed, and was quiet for the longest time.

"Flynn, Flynn," he sighed, "what _am _I going to do about you? That MAD potion was the strongest potency you can legally make, and it still doesn't seem to be working."

"Yeah..." Phineas looked away nervously. "I really don't know what to say." As he looked away, Phineas thought of a question.

"Hey, Professor Flitwick?"

"Yes, Phineas?"

"Um...do you have any idea...what my MAD potion would do... if the recipient were...I dunno, a _Muggle_?"

Flitwick let out with a hearty laugh. "A Muggle! Well, I'm not entirely sure..." His eyes suddenly lost their happy luster and looked serious. "Have you been sending this potion to any Muggle relatives?"

"Oh, no," Phineas said.

"Good!" Flitwick laughed again. "Well, in that respect, then...I suppose it would greatly increase their chance of catching diseases...giving off ultraviolet radiation... exploding... spontaneous combustion... Are you all right, Phineas? You look a bit pale."

"I'm...I'm fine," Phineas wheezed, his eyes as big as dinner plates. "I've got to catch up to Ferb now..."

Phineas fell out of his chair and staggered out of the Charms classroom.

"Yeah..." Phineas said, walking next to Ferb, glaring at his vial of MAD medicine. "I'm never drinking this stuff again."

With that, Phineas Flynn 'accidentally' dropped his vial over the castle railing and into the Hogwarts Lake.

Or so he told Filius Flitwick the next morning.


	19. Meap Advises Our Cartoon Friends

A/N: I don't own Harry Potter or Phineas and Ferb. Man, I know it's good to remember these things, but they're pretty dull and distracting from the story! Read and review, _s'il vous plaît_.

It was late in the afternoon, when Harry, Ron, Hermionie, Phineas, and Ferb were sitting in the courtyard, simply chatting, as they had been before. Hermione was complaining about schoolwork not being hard enough, and everyone else was discreetly rolling their eyes.

"Harry!" someone cried from the staircase. "Phineas!"

Everyone looked to the source of the noise. Neville was bunny-hopping towards them, waving his arms frantically. His legs were, apparently stuck together.

"Harry!" he yelped again. "I was hit by a Leg-Binding Curse by one of the Slytherins!"

Hermione sighed. "Honestly, Neville, don't you know the countercurse? It was on page twenty-three of our Standard Book of Spells and was stated as being self-applicable and –"

"Just get it off!" Neville moaned.

Hermione lazily pointed her wand at Neville. "_Finite Incantatem_!"

Neville fell forwards with another yelp and landed on the dusty courtyard floor. He picked himself up and dusted himself off, relieved.

"Thanks," he muttered, trying to catch his breath from all the hopping. "Thanks very much..."

"You okay, Neville?" Phineas asked.

"Yeah, I'm fine. I need to get up to the commons now." He reached into his pocket for his wand, and then pulled something else out.

"I've got a chocolate frog card, if you want it," he told them. "Harry collects them, don't you, Harry? Bye," he said, handing the card off to Ferb and trudging towards the commons.

Ferb took one look at the card and then gave it to Ron.

"Dumbledore again," Ron sighed. "I've got loads of him. I think he was the first one I ever...Guys!" he shouted suddenly. "Look at this!"

The five first-years crowded around Ron, who pointed to a small bit of text below Dumbledore's moving picture. "Look, _Dumbledore is famous_, blah blah blah, _and his work on alchemy with his partner Nicholas Flamel!" _

"Who?" Harry asked blankly.

"Nicholas Flamel!" Hermione shouted, making them all jump. "I read about him! He's famous for making _the Philosopher's Stone_!"

Phineas nodded. "I think we know what that dog is guarding, and what was in vault 713."

The next day was the Gryffindor match against Slytherin. Everyone was anticipating a very close game, but Harry located and grabbed the Snitch in less than five minutes. It was one of the shortest matches in Hogwarts History. Phineas and Ferb congratulated Harry on his quick playing after the match.

"Man," Phineas said wistfully, "I wish _I _could ride a broom."

"You can't?" Harry asked in surprise.

"Nah, I'm a Muggle. They don't seem to work for us."

Harry left the field with Phineas and Ferb to put his broom back in the broom shed. He was about to fasten the lock when he saw something out of the corner of his eye...

"Phineas, Ferb," Harry said in a quick whisper. "Look over there."

Snape was gliding across the castle grounds, in a long, black cloak, obviously not wanting to be seen. He walked around the castle corner and out of view.

Harry narrowed his eyes and mounted his Nimbus 2000 again. "Get on, guys – let's see what he's up to."

Once the three of them had gotten onto the broom, Harry kicked off the ground and guided his Nimbus 2000 through the air. They hid behind castle towers, watching Snape glide across the Hogwarts grounds and into the Forbidden Forest.

"Isn't that place forbidden?" Phineas asked.

"Shh!" Harry admonished. He circled over the trees, but they were very thick, and they couldn't see anything.

"Get closer to the ground, Harry," Phineas said. "Maybe we can listen in to where he's going."

Harry floated lower to the trees, and all three of them were careful to keep quiet.

"d-don't know why you wanted t-to meet me here, Severus, of all p-places..."

"Oh, I thought we'd keep this private," Snape said.

Harry, Phineas, and Ferb all blinked at once. Snape was meeting with Professor _Quirrel_?

"Have you found out how to get past that beast of Hagrid's yet?"

"B-b-but Severus, I..."

"You don't want me as your enemy, Quirrel," Snape said, stepping closer to Quirrel. His voice was cold and deadly.

"I-I don't know w-what you – "

"You know perfectly well what I mean."

Just then, an owl hooted, and Phineas fell off of his broomstick in shock. In panic, Harry leaned over and caught Phineas by the ankle, just before his triangle-shaped head hit the leafy canopy. They pulled Phineas back on the broom in time to hear Snape again.

"- your little bit of hocus-pocus. I'm waiting."

"B-b-but I d-don't..."

"Very well," Snape sneered. "We'll have another little chat soon, when you've had some time to think about where your loyalties lie."

It seemed the conversation was over, so Harry steered his broom back to the shed and lighted down.

Phineas got off and shook. "_Man_, that was close. What the heck was Snape doing out in the Forbidden Forest with Quirrel?"

"Threatening him, by the sounds of it," Harry concluded. He gasped and shook Phineas by the shoulders. "Phineas! I've got it! Snape is after the Philosopher's Stone!"

Phineas pulled away from Harry, feeling a bit dazed. "Let's not jump to conclusions, Harry," he cautioned, but Harry wasn't really listening.

"Snape wants the Stone! He'll make gold and live forever, and no one will oppose him! Snape wants the Philosopher's Stone! It all makes sense! I can't believe I didn't think of it before..."

"Harry," Phineas said curiously, "you don't suppose this is one of those times where someone is 'obviously' doing something and it only happens to be a distraction so that the reader is really shocked later on in the story, do you?"

Harry waved him away. "Of course not! Snape's always been evil, and Hermione says he used to be a Death Eater, and _Snape wants the Stone_!"

Phineas and Ferb awkwardly left Harry to rant about his own cleverness and headed off for their Astronomy class, which was always at night.

Their teacher had instructed them to search for messages in the stars that night, but Phineas was unfocused. Eventually, he just gave up and sat down on the castle railing. Ferb came up to the telescope and searched for him.

"I just don't know anymore, bro..." Phineas sighed. "Who to trust, who not to trust, what to do...Snape and Quirrel, Flitwick's potions and everything...what do we do?"

Ferb looked up from the telescope. "I don't think we should trust Quirrel."

"Oh? Why do you say that, Ferb?"

Ferb backed up from the telescope. "I read it in the stars."

"Really? Can I see?" Phineas asked curiously. He put his eye up to the telescope.

Out in space, a pink and white, blue-eyed alien was sailing past in a spaceship. He was holding up a sign out the window that said _DON'T TRUST QUIRREL_!

Phineas backed away from the telescope and smiled.

"Well, I guess the stars don't get much clearer than that, do they, bro?" he stated, matter-of-factly.


	20. The Baby Dragon Dilemma

A/N: I do not own Harry Potter or Phineas and Ferb. Wish I did, though. Read and review, please.

In the weeks that followed, it seemed that Meep's tip wasn't very accurate. Quirrel failed to do anything suspicious, and Snape grew more despised by any non-Slytherin student by the day. Exams were less than ten weeks away, and Hermione was subsequently never seen without a book in hand.

As another result, Hermione often dragged Harry, Ron, Phineas and Ferb along with her to the library, which they never objected to, but found deadly boring.

One day, however, as Phineas and Ferb were busy experimenting to pass the time, something interesting happened.

Everyone was busy staring out the window, waiting for Hermione to be done. They were all so bored that they nearly missed the heavy shuffling sound from the library.

"Hagrid!" Ron shouted in surprise.

Hagrid stepped out from behind a bookshelf. "'Allo, Ron. Jus'...er, getting' some stuff. Y'know...stuff..."

He hid some books behind his back and back stepped out of the library. His eyes were twinkling with excitement. "Hey, if ye and Harry and th' rest want to come to m'shack, I've got somethin' special in store!" He winked at them and then hurried out of the library.

Ron grumbled. "Hope it's not more rock cakes..."

That evening, after classes, the five friends snuck out of the castle at dinner and used Harry's invisibility cloak to cross the Hogwarts grounds to Hagrid's little wooden hut. They knocked on the door, surprised to find all the shades drawn.

"Who's there?" Hagrid bellowed. He opened the door a crack. "Ah, 'Arry, good...jus' wanted te make sure..."

Hagrid let the five of them into the hut. Fang slobbered all over them, but Hermione had brought a book along and was mortified that Fang would get drool over it.

As Hermione was pushing Fang away, she noticed a stack of books on Hagrid's table. "Oh, are these the ones you checked out today?"

Hagrid rushed to the table and tried to hide them. "Er, yeah, but you'll not be wantin' to look at them, trust me..."

Hermione leaned around him and caught a glance at the titles. "Oh, Hagrid! What is that, _Dragon Breeding for Pleasure and Profit_? Dragon breeding was outlawed by the Ministry ages ago!"

Phineas straightened up abruptly at this. "Dragons? Are there dragons here?"

"Here? Nah, don' be silly, Phineas, there aren't any dragons here!" Hagrid laughed, rather forcefully.

"I meant in England."

Hagrid relaxed, and inched toward the fireplace, which was blazing all the while. "Oh, in England...yeah, there be dragons 'ere...Welsh, I think..."

Hermione, ever nosy, was now peering into the fire. "Hagrid..." she said, slowly, her eyes widening.

Phineas, Ferb, Harry, and Ron soon followed.

Hagrid beamed with pride. "Yeah, I got a real dragon's egg! Won it from a stranger in a game of cards a few nights ago...It's a Norwegian Ridgeback. They're rare, them!"

"_Hagrid_," Hermione said, trying to talk sense into him. "You live in a _wooden house_!"

"Do I?" he asked absentmindedly. He began stoking the fire and humming a little song. "I always wanted a dragon!" he said happily. "Ever since I was a lil' kid..."

Phineas frowned. "Wait. So, a random dude at a bar just _gave_ you a dragon egg?"

Hagrid shrugged his shoulders. "Er...well, not 'xactly...W'had a few drinks...th' rest is kinda blurry... we were talkin' bout monsters, and I mighta mentioned Fluffy –" Hagrid suddenly clamped his hands over his mouth.

Harry stared. "Fluffy?" Then quite a few things clicked in his head and he stood up in shock. "Snape said something about 'that beast of Hagrid's'! Hagrid, did _you _lend that three-headed dog to guard the trapdoor and the Philosopher's Stone?"

There was a crashing thunder as Hagrid jumped. "What? I don' know _nothin'_ bout the Philosopher's Stone!" Hagrid paused. "And he's not just Fluffy. 'Is real name is Mister Fluffy Pants, 'cause he's fluffy, and 'e looks like he's wearin' pants. Plus, 'e reminds me o' my uncle Fluffy Pants."

Hermione rolled her eyes. "_Hagrid,_ we know about Nicholas Flamel and the Philosopher's Stone. Harry _also_ heard Snape saying that you had a monster guarding it. This is _serious_! We're pretty sure that Severus Snape is trying to steal it!"

"Steal it?" Hagrid laughed. "Snape's helpin' te _protect _the Stone! A lotta teachers are, let's see...there's McGonagall, Sprout, Flitwick, Fluffy's _mine_, Snape, and Dumbledore did somethin'. That Stone's _safe _as anythin'."

"Well," Ferb said, as the five of them turned to leave. "I do hope that that wasn't one of those statements that turns out dreadfully ironic later on in the plot."


	21. A Rabbit with a Blender Saves the Day

A/N: I do not own Phineas and Ferb or Harry Potter. The action picks up soon, so please keep reading!

The egg gave a frantic little quiver, and the black shell split in half. Something wet and black, which looked like a slimy umbrella, plopped out.

Phineas and Ferb, in doctor's aprons and face masks, who had the egg on a surgical table, threw their tools into the air.

"It's a boy," Phineas told Hagrid, handing him the dragon hatchling.

"I'll call 'im Norbert!" Hagrid said, his voice shaking with joy. "Hey, there, Norbert, how're ya?"

Norbert squeaked and bit Hagrid on the finger.

"Oh, lookit that, he knows his Mum!"

"That bloody dragon _bit_ you, Hagrid!" Ron exploded. "It's not a thing about affection."

Hagrid was swinging Norbert around his hut happily, when suddenly Hagrid's eyes opened and he shoved Norbert behind his back.

"Harry!" he yelled. "Close the drapes! Quick!"

Harry rushed up to the window, and as he did, he saw a boy run away from the tiny shack and up to the castle.

"Malfoy!" Harry threw the door open and began to race after Draco Malfoy, but Malfoy had already reached the castle doors and entered.

"We've been seen!" Harry told them.

"We need to get rid of this dragon, Hagrid," Hermione told him. "Why don't you just let him go free?"

Hagrid began crying. "What? Bu...bu...he's only a baby! He'll _die_!"

Phineas smiled and turn to his stepbrother. "Wow. How coincidental that this should happen _just after _the dragon hatched."

"I've got it!" Harry said. "Ron, your brother Charlie works with dragons in Romania! They can take baby Norbert!"

Harry growled and hit the table. "We need something _faster_!"

"We've got some time to think, Harry, don't worry." Hermione smiled and put her hand on his shoulder. "Hey, in the book, Malfoy hung on to the information for a really long time. Charlie will have recovered by then!"

Suddenly, a piece of parchment paper materialized in the cottage. Phineas plucked it out of the air and read with puzzlement.

"_Dear Fanfiction characters_," he read, frowning. "_Due to the interest of time and maintaining an interesting story line that does not bore the audience by dragging its feet, and due to the sheer whim of the author who wants to get to the action, we regret to inform you that MALFOY WILL DELIVER THE INFORMATION AS SOON AS HE ENTERS THE CASTLE?!_ Phineas read, screaming the last sentence in shock. "That's not _fair_!"

Ron started running around the hut in a panic. "_WHAT'RE WE GOING TO DO? WHAT'RE WE GOING TO DO?"_

Hermione swooned on the spot. "I'll be...I'll be..._EXPELLED_!"

"Wait!" Phineas said. He took out his Random Thing Flinger. "Maybe _this _will help us with our situation! I bet we could summon an _airplane _with this thing!"

He pulled the trigger.

A xylophone and a pair of mallets spewed out.

"What?"

Ferb shrugged. "Well, _random _and _beneficial_ are, after all, two completely different things."

Hermione looked out the window. "_Guys_," she said in a strangely high voice, "_Professor Snape and the other teachers are coming to the shack_!"

Phineas straightened up suddenly, and hopped up on Hagrid's table with a triumphant grin. "Ferb, I know what we're gonna do today! Now, everybody listen to me..."

"In there!" Malfoy said with a sneer, pointing at Hagrid's hut.

"Good work, Draco," Snape congratulated.

"Dear, dear," Flitwick muttered, looking at the little shack. "If they've really got a dragon, the consequences..." his voice trailed off.

"Oh, you're just worried about your own House points," Professor Sprout said.

"Come out, students!" Professor McGonagall called out wearily. She wasn't saying anything, but was also obviously dreading the points that would be taken from Gryffindor.

"_THERE! THERE!_" Snape exploded suddenly, pointing at the window with glee. "Look, there's the dragon!"

Sure enough, silhouetted against the window was the shape of something that looked extremely like a dragon. They could obviously see the rectangle-shaped head, long, skinny, neck, and the body with a bunch of little spikes.

Snape, in triumph, stormed up to the window and fixed his wand on the window. "_Evanesco_!" he cast, the Vanishing Charm.

The teachers all gasped as the window and drapes vanished in the night, and they saw what was behind the window.

Snape blinked. "Marty the Rabbit Boy and his Musical Blender?"

Marty the Rabbit boy was laying on his back, holding his blender over his head. The 'neck' had been his arms, and the 'head' had been the blender. The 'spikes' on the dragon were his ears.

"Yeah, that was me," Marty the Rabbit Boy said guiltily. "Hey, guys," he said, waving to them happily.

"Don' blame the students," Hagrid pleaded on their behalf. "I called 'em here 'cause...'cause Marty was here! Thought they'd like to see, y'know...?" He stepped back, hoping that the teachers couldn't see the dragon he was desperately trying to hide behind his back.

The teachers all groaned sleepily and started trudging back up to the castle.

"What a waste of time," Professor Sprout muttered.

"Getting out of bed for _this_?" Flitwick shook his head. "Snape, I think you need a pair of glasses."

Snape looked around, bewildered. "B – b- but-"

"I'm the sp-sputtering one, S-Snape," Quirrel said as he passed, hiding a laugh.

Draco was also upset. "What did you do with the dragon?" he demanded of them.

"What dragon?" Phineas asked, smiling as if to say, _Prove there _is _one._

Draco looked around, his face reddening. He scowled at them.

"No glory for you, eh?" Ron asked, laughing. "No points to Slytherin, no getting to laugh at us..."

"I don't need to show the teachers a dragon to laugh at _you_, Weasley," Malfoy sneered. "This little shack of Hagrid's must seem like a _palace_ compared to _your _house."

Ron was the one to redden now. He tried to say something, but caught the words in his throat. They would have only served to get him in trouble.

"Hey, back off, dude!" Phineas yelled. "Go pick on someone your _own _size!"

"Yeah," Malfoy laughed. "Because _you're _obviously not my size. How old even _are _you? Two, three...?"

"Get _lost_, Malfoy," Harry growled, taking out his wand.

Marty the Rabbit Boy took his Musical Blender and stood up. "Well, I'll be going now. Mind if I take the xylophone?"

"Who _is _that freak, anyway?" Malfoy sneered.

Marty the Rabbit Boy gave Draco a dirty look and got back in a battered contraption he had found on the opposite shore, labeled M-OTOR-BO-AT. He held out a bit of worm for the wild platypus that had become trapped in the hamster wheel and started off across the lake. His Super American Pop Teen Idol Star World Tour van was waiting on the regular road.

"That was Marty the Rabbit Boy and his Musical Blender," Harry informed him.

Malfoy was about to turn around, but saw an opportunity. "I didn't mean _him_. I meant that triangle-headed freak by Hagrid."

Harry, Ron, Hermione, Phineas, and Ferb acted too fast to see the individual spells, but the affects were loud and bright.

"_Mucus Ad Nauseam!"_

_ "Tarantallegra!"_

_ "Furnunculus!"_

_ "Orchideous Oppugno!"_

_ "..."_

Malfoy was flung back several feet, as five spells hit him at once. First, his nose began running and boogers flew out everywhere, then his feet began a frenzied, uncontrollable dance. Then, his face became covered in boils, and conjured flowers began to attack him. Last, but not least, His hair became purple with red polka-dots that spun around.

"_POTTER! WEASLEY! GRANGER!_" Professor McGonagall shouted, running back to the scene.

"_FLYNN! FLETCHER!_"

"LOOK AT THIS!" McGonagall said, helping Draco up, and wincing as she saw he was covered in snot. "What have you _done? _Have you lost your _minds_? What were you thinking, jinxing another student like that? You'll be lucky if Gryffindor has _any _House points..."

Flitwick was also speaking quickly and loudly. "What a spell! And nonverbal, too! Ferb Fletcher, such an imaginative use of the charm! Absolutely brilliant, I've got to..."

McGonagall shot Flitwick a deadly look.

"Er...well, poorly done, boys...that'll cost some House points, I'm afraid..."

Filch, ever creepy, had snuck up behind Phineas and Ferb and grabbed them both by the shoulders.

"Well, well, well," he said in a quiet, stalker-ish voice. "We _are _in trouble..."


	22. Coconuts in the Forbidden Forest

A/N: I don't own Phineas and Ferb or Harry Potter. Now, get on with it!

Harry seemed miserable to Phineas. He had cost Gryffindor the lead he had earned in the Quidditch tournament for House Points, and Hufflepuff and Ravenclaw seemed to hate him, too, because now Slytherin would win _again_.

Ravenclaw had been second place and was now in third, below Hufflepuff. But Ravenclaw didn't have much of a chance for winning the cup in the first place, so the Ravenclaws didn't seem to be angry at Phineas and Ferb.

Besides, Ferb had invented a new nonverbal spell and Phineas had made a _Lauren Hartfield, Hufflepuff _reference, both while _simultaneously_ showing up a Slytherin. It earned them a bit of fame in their House.

All of this only served to make Harry, Ron, and Hermione more depressed.

The only blemish in Phineas and Ferb's life, and the major one in the three Gryffindors', was the looming detention with Filch. About six days before exams were due to start, all of them received a letter from their Head of Houses.

Phineas sighed at the breakfast table as Perry the Platypus hopped on the table and set the letter down. He made his platypus chittering noise and let Phineas pet him.

_Phineas and Ferb_,

_Your punishment will, regrettably, occur at eleven o'clock tonight. You're due to meet Filch in the entrance hall._

_**Filius Flitwick **_

_P.S. Just in case, for some, __freakish__, __abnormal__, __totally__out of the ordinary__, odd reason, you don't make it back from your punishment __alive__... could you please write down the mental incantation for the spell Ferb worked? Thanks in advance! _

"Well, that's cheery," Phineas stated, stirring his pumpkin juice absentmindedly.

In the great entrance hall, where the House Point Glasses stood, Phineas and Ferb met Harry, Ron, and Hermione.

Hermione was in tears. "Just think, I could have been _studying _tonight, I _could have been studying!_ I'm going to fail all of my exams this year, and it's that ruddy dragon's fault! I could have been - "

"Oh, be quiet," Ron said, rolling his eyes.

"Well, here we all are," Filch said quietly, appearing behind them very creepily. Everyone shuddered and whirled around to see him.

"Yes, that's right," Filch continued. "Ready for your punishment? Dumbledore says I can't hang you upside-down by the ankles and torture you, but we'll still have a grand time, won't we?"

Filch led the five friends out of the castle and down to the ground. Surprisingly, the stopped back at Hagrid's hut.

"The scene of the crime," Filch snarled. "Hagrid! Get out here and take these little brats!"

The door of the hut swung open. Hagrid and Fang walked out, Hagrid carrying a lantern. "Right! Well, here y'are... all five of ye...off we go!"

"Where are we going?" Harry asked.

Filch answered. "The Forbidden Forest." He cackled manically.

"I'd rather be in the Forbidden Forest without Filch than anywhere else _with _him," Phineas said, as they walked away from the warm lights of the castle.

"Why are we going to the Forbidden Forest?" Hermione asked, her voice and knees shaking.

"Unicorns," Hagrid answered immediately. "I've been findin' them dead er wounded a lot lately. I've started trackin' one that's wounded; it's been leavin' a trail of blood, poor thing."

"Is that that silvery goo?" Phineas asked, pointing to a faint line of iridescence that snaked through the forest.

Hagrid nodded. "Yep." He stopped suddenly, and turned around to face the students. "Right. 'Ermione, Ron, and Ferb, yer comin' with me. 'Arry and Phineas are takin' Fang and goin' _that _way."

"Why are we splitting up?" Ron asked in a high-pitched voice.

"Oh, it's just th' Forbidden Forest...yu'll be fine there, 'Arry and Phineas. Be seein' yer..."

With that, Hagrid, Hermione, and Ron left.

"Let's find the unicorn," Harry said. "The sooner we do, the sooner this is over."

Together, Harry and Phineas crept through the creepy forest. Every little noise, every little movement, made them jump.

"Hey, look!" Phineas said, pointing to the ground. "It's a line of spiders, all going in the same direction! Wonder what that's for?"

"Next book, next book," Harry muttered.

They continued to trudge through the forest, too afraid to talk, almost too afraid to breathe, when both of them suddenly stopped short.

Their blood ran cold.

In front of them was a unicorn – very beautiful and very dead. The silvery liquid, blood, was seeping from a wound in its side, and a cloaked figure was hunched over it.

The figure swung its head towards them, and the unicorn blood dripped from its mouth.

It had been _drinking the blood_.

Harry screamed and broke the silence. He fumbled for his wand and shot sparks in the air, trying to alert Hagrid. Suddenly, he doubled over with pain – his scar was burning intensely, as if it might burst.

Phineas saw the figure _slither _closer, and saw Harry clutch his forehead in pain.

"Harry!" Phineas yelled.

"_I can't do...anything_," Harry said, through the pain.

The figure was nearly upon them now, Phineas could smell cold, slimy, terrible things, and he saw the bloodstains on his cloak, but his wand hand seemed frozen.

"_DO SOMETHING_! Harry exploded, falling to the ground in pain.

Phineas gulped, and then stared at the figure.

He pulled out his Random Thing Flinger and pulled the trigger.

There was a chirping noise, and a swallow with a coconut tied to its leg exploded out of the barrel. It flew up in the air, just above the scary figure, but then the weight of the coconut became too much. Really, it's a simple matter of weight ratios: A ten-ounce bird simply cannot carry a two-pound coconut.

The string connecting the coconut to its foot _snapped _in half, and the coconut fell squarely on the figure's head.

It swayed back and forth, as if struggling to keep consciousness. The figure shook its head and tried to advance towards Phineas again.

Then, of course, the swallow dive-bombed the figure and began attacking its head.

A dreadful hissing noise came from the cloaked figure as it tried to protect itself. It stumbled off into the forest, dripping unicorn blood as it went.

"'ARRY!" Hagrid yelled, thundering up to them. He helped Harry to his feet. "Yer all right there, 'Arry? Phineas?"

"I'm...fine, I'm fine," Harry assured, slowly letting go of his scar. He looked at Phineas. "I think you just saved both of our lives."

"Nah, that was the swallow," Phineas said happily.

Hagrid glanced around nervously. "Yep, there've been things in the forest, things I haven't seen b'fore...best we got yer back to the castle. Sun's nearly up."

"Hagrid," Harry said suddenly. "We were attacked by this... this _thing_. It was drinking unicorn blood, but why?"

"Well, 'Arry, unicorns are beautiful, innocent creatures," Hagrid said darkly. "Their blood 'as magical properties, and will bestow life upon a man, even if he be an _inch _from death. But there's also a curse – th' moment that blood touches yer lips, you've got yerself a 'horrible, cursed life."

Harry blinked. "If it's that bad, why drink it in the first place? Wouldn't it be better to die?"

"Not, 'Arry,' Hagrid continued softly. "Not if ye only want ter drink the unicorn blood for a while, until ye get a _full _life by other means."

"The Stone?" Hermione asked.

"But who'd want to kill Harry like that?" Phineas asked, concerned. "And who's, like, half dead?"

Hagrid started to walk up to the castle. "Who tried ter kill 'Arry the first time? Who gave 'im that scar?"

Harry gasped. "Then that was _Volde_ – "

"SHHHH!" Hagrid hissed. "Not 'ere, 'Arry. Let's get up ter the castle."


	23. Through the Trapdoor (Finally!)

A/N: Well, the holidays are finally over, and I'm pleased to say that I received some rather good stuff, mostly Phineas and Ferb related. In fact, as I'm writing this, I'm listening to _Squirrels In My Pants_ on a CD I got.  
Brief overview of chapter: This is the one in which Phineas and Ferb (and the three Gryffindors) make their way Through the Trapdoor! Candace also comes back into play, so read and review, as always! I know that most of the previous chapters haven't been exactly thrilling, but that stops right here! I just needed to make a reference to Sir Cadogan before so I could bring him up here and make an epic reference! I don't own Phineas and Ferb or Harry Potter. This is a pretty long chapter, but this is going to be very exciting and funny!

Exams had finally come. Phineas and Ferb had most of their classes together, so they got to see how the other did.

For Phineas, the worst exam by far was Charms. How _the heck_ did one make a pineapple tap-dance across a tabletop with science? The spell he had to program was _humongous_, with at least four hundred and twenty instructions. Even with all that planning, the pineapple just barely hobbled around. Phineas hoped that Flitwick didn't notice the rather strong cyclonic winds that were propelling it.

Potions was relatively easy, Astronomy went astronomically, History of Magic was boring but also pretty easy, and Transfiguration wasn't _too _bad (Phineas just bent light around the object so it appeared different, and made sure McGonagall didn't touch it).

Once exams were done, the entire school seemed to breathe a sigh of relief. Phineas and Ferb were, one lovely evening, spending time at Hagrid's hut with their three Gryffindor buddies when a fateful question was asked.

"Hagrid?" Hermione inquired.

"Uh, yup?"

Hermione frowned and crossed her arms on the table, looking troubled. "You told us that you won the dragon egg from a game of cards with a stranger."

Hagrid rubbed his head. "Yeah, that's right."

"What did the stranger look like?"

He shrugged. "Dunno. He was wearin' a black cloak and coverin' his face."

"And you told us that you might've mentioned Fluffy, the dog guarding the Stone, to him?"

"Told ya – I dunno. He bought me a few drinks, and the rest is kinda blurry." Hagrid sat down and tried to jog his memory. "Let's see...he asked if I could handle a dragon, and I said that a dragon'd be easy after raisin' Fluffy. Seemed kinda curious 'bout Fluffy, I think. He asked how I coulda kept Fluffy under control, a big dog like that. I told 'im that Fluffy was jus' fine if ye played 'im some music, it really calmed him down..."

The conversation dropped.

"Dude! You just told a complete stranger how to get past Fluffy!" Phineas exploded. "That was, like, the _only thing _that's been protecting the Sorcerer's Stone!"

"We need to go!" Hermione said, standing up immediately. They thanked Hagrid and pretty much ran all the way up to the castle.

"We need to tell Dumbledore!" Ron said to them. "He'll stop Snape before anything happens!"

Ferb blinked. "Except for the fact that Dumbledore has, quite conveniently, left the castle for the day."

"It's _amazing _how that happens," Harry growled under his breath. "What did he say again, _Ministry trip_, right?"

Phineas shrugged and smiled. "Well, guess it's up to us. Shouldn't be _that _hard to stopped a trained, talented, probably manically depressed teacher, right?"

Phineas, Ferb, Harry, Ron, and Hermione all snuck upstairs to the Charms corridor they had been running down while running from Filch.

"Still locked, I suppose," Harry said, jiggling the handle to the Forbidden door.

The door swung upon and slammed against the wall behind it. Mr. Fluffy Pants, who had been sleeping peacefully, snapped awake and began to growl.

"Great!" Harry said, as the dog swung its massive heads towards them, eyes rolling in hunger. "And we _could have _snuck past it to the trapdoor!"

"We're _dead_!" Ron screamed, covering his head and beginning to sob, as Fluffy ran towards them, teeth bared...

"WHAT HO, good sirs and noble lady?" Sir Cadogan yelled, running into the room with them. "I saw you come up to the corridor and..."

Sir Cadogan saw the dog charging at them. "_GREAT SCOTT_!" he screamed, and bolted out the open door.

If our heroes had been able to accompany the odd pair, they would have seen Fluffy following him, growing and barking with hunger, all the way down the Charms corridor, making a noise and a mess as he ran through.

"_HEAVENS ABOVE, YOU KNAVE, I SAY, BE OFF WITH YOU!_ Sir Cadogan screamed, at the top of his lungs. "_BE OFF AND NE'ER RETURN, DEMON!_"

Naturally, Sir Cadogan's screams merited some attention as they cavorted through the school. Students and teachers rushed out to see what the noise was, and screamed themselves as they witnessed a ghostly knight being followed by a three-headed dog.

"It's the Ghost of the Black Knight!" a first-year Hufflepuff girl shrieked. "And his Hounds of Heck!"

Our heroes, however, were too busy staring out the open door with surprised, dumb gratefulness as they saw the very big and scary dog leave them to go bother Sir Cadogan.

"Next obstacle," Phineas said happily, walking to the trapdoor and heaving it open. He stared down into its depths, trying to see what was below.

"It's too far down," Phineas told them. "Even with wandlight, it's pitch-black."

Ferb blinked. "I believe that some things call for a leap of faith."

"Right!" Harry said. "All of us, on the count of three...One, two, _THREE_!"

The five of them, closing their eyes, leapt through the dark trapdoor. The wind whistled past Phineas's ears, and he braced himself for something hard, or maybe a moat of water...

Everyone was doing likewise, so it was a bit of a shock when they landed on something very soft and squishy.

"I'm alive!" Ron squeaked. "I'm alive!"

"What exactly did we _land_ on?" Phineas asked. He poked the soft and squishy something.

The Devil's Snare convulsed before wrapping its tentacles around each of the students.

"What IS THIS?" Ron screamed, thrashing around. "It's got me tied up!"

Phineas laughed. "Devil's Snare! Classic," he said, winking at Ferb. "See you all at the bottom!" he said brightly.

With that, Phineas Flynn and Ferb Fletcher fell through the Devil's Snare and out of sight.

Hermione gasped. "Oh, Devil's Snare! Everyone, just _relax_. It'll let you go if you don't move!"

"It _ATE _them!" Ron screamed. "It _ATE _Phineas and Ferb! It'll _kill _all of us!" He struggled against the vines, but they only tightened.

Hermione and Harry, who had been trying to relax, also slid out of sight.

"_HARRY! HERMIONE! IT __ATE__ YOU!_"

"_Relax_, Ron!" Hermione called up to him. "If you struggle, it'll strangle you!"

But Ron was panicking too much to listen to them. The vines tightened around him, muffling his screams.

Phineas, cool as ever, stood right below where Ron was and raised his wand up in the air. He cleared his throat. "Wand, produce a concentrated beam of light."

A bright ray shot out of Phineas's wand, and the Devil's Snare made a strange _eeking _noise. It receded from the light and dropped Ron on the hard ground beneath it.

"_Oof_," Ron said, falling flat on the ground. He sat up and rubbed his head. "That was the single most terrifying experience I've ever had in my life."

"Well," Phineas said happily, "we should probably finish making our way through the corridor before you say something like _that_." He pointed heroically onwards. "Let's proceed, guys!"

Using their wands for light, Harry, Ron, Hermione, Phineas, and Ferb made their way to a new room, which had strange birds buzzing around the ceiling.

Harry stared up at the birds. "Do you suppose they'll attack if we cross the room?"

"Let's go really slowly," Hermione suggested.

After a few creeping footsteps, the flying birds didn't react. Relieved, the five friends crossed the room to another door.

"Hang on, _this _one's locked," Harry proclaimed, trying to turn the handle.

"How do we get through?" Ron asked.

Harry glanced up at the birds. He observed them very closely.

"Keys!" he exclaimed suddenly. "They're not birds, they're _keys_!" Harry ran around the room, looking into the dark corners, until he found what he was looking for.

"A broom?" Ron asked. He blinked. "So you've got to catch a key?"

Harry mounted the broom, obviously pleased to take the opportunity to show off.

"Well, yes, Ron. I admit – it'll tax my skills and my strength. But rest assured!" he roared. "I will do _anything _to deliver my friends and school from danger, even if I have to put my _own life_ on the line."

Heroically sighing, Harry prepared to lift off. "If I die in the attempt, go on without me. But remember me as the Gryffindor I always was: _fearless_, _selfless_, and – "

"Well, actually," Phineas interrupted, "Ferb can just open the door with his harmonicas."

Ferb took out one of his harmonicas and, after a short pause, played a single note.

The door seemed to shake a bit. Then:

"_That'll do_," it said, and swung outwards.

Harry stood, uncomprehending. He watched his friends file out of the room without witnessing his amazing broom skills. "But...but...but...but..."

Harry sighed and looked sadly at the broom. He dejectedly leaned it back against the wall, giving it a loving pat before rejoining his friends.

In the next room, the floor was a giant chessboard, and life-sized chess figures stood on the squares.

"A chess set!" Ron exclaimed. "This is _my _forte, guys! Let's see," he muttered, pacing back and forth. "No doubt that this wizard chess set knows a _lot of _strategy, and will be hard to defeat..."

Phineas cleared his throat. "Well, that's not necessarily true. Why don't we start with something simple?"

"Like what?" Ron asked.

Phineas walked out onto the chess board and pointed to some figures. "Well, the most basic way to win a chess game is with five simple moves. Why don't we start with that?"

Five moves later, the three Gryffindors and two Ravenclaws had checkmated the opposing side.

Ron whistled. "Wow. That was the shortest game of chess I've ever won."

As the other king threw down his crown in defeat, an unseen door on the other side of the room opened up.

"Hey! Look!" Phineas exclaimed. He bent over and picked up a small package on the ground. "Victory Gum!" Phineas tore the gum pack open and pulled out a slim card.

"What's that?" Hermione demanded, peering over his shoulder.

"An existentialist trading card. Oh, man, Nietzsche!" Phineas said excitedly. He and Ferb high-fived.

Harry and his friends peeked at the package.

**"**_**VICTORY GUM!**__**Even if you win by forfeiture!"**_

"And we _didn't_," Phineas said smugly. He pocketed the gum and the card. "Onwards, friends!"

The next chamber was dark and damp. Just as the five friends stepped through the door, it slammed shut behind them.

Hermione lit up her wand, and as light flooded the room, everyone jumped back.

"TROLL!" Ron shrieked, jumping behind her for protection.

"Relax, Ron!" Hermione snapped, rolling her eyes. "It's knocked out."

Harry sighed with relief. "Well, I'm glad that Snape did _something _useful for..."

"_PHINNNNNNNNNEEEEEEEEAAAAAAAA AAAAS! _

Everyone jumped back with horror as the gravelly, rumbling voice shook the walls of the chamber. The shadow of a monstrous figure was cast upon the wall with their lights, with serrated claws and what seemed like a club.

"There's another one!" Harry screamed with terror.

"We're _DOOMED!_ Ron screamed. "Another big, ugly, troll!"

"It's _hideous__!_' Hermione screamed, shielding her face.

"It's _monstrous__!"_ Harry screamed after her.

Phineas blinked. "Hey, it's Candace!"

"_PHINEAS!_" The gravelly voice sounded again. From the shadows, a red-haired, red-faced teenage girl appeared. She stormed up to Phineas and waved a tiny Devil's Snare at him with rage.

"What _is _this thing?" Candace demanded. "Get it off of my arm, _this instant_!"

Phineas smiled. "Sure, Candace." He grabbed Harry's arm, which held his lighted wand, and touched the Devil's Snare. The plant shriveled up, and the pot fell to the floor.

"Who _are _you?" Ron asked timidly.

Candace coughed, and the wild parsnip allergy wore off. She glared at Ron. "Who are _you_?"

Phineas grabbed Candace by the hand. "What a coincidence you're here, Candace! These are our friends at school, Harry Potter, Ron, Weasley, and Hermione Granger! Guys, this is our sister, Candace!"

A pause.

"Is _every _member of your family bound and determined to break into Hogwarts?" Hermione asked, peeved. "This is supposed to be a Muggle-free zone."

"Look, _sister_," Candace growled, "I didn't _ASK _to come here, 'kay? One minute, I was in my Panic Room because my dweebs of brothers sent me _that_!" She pointed angrily at the smashed plant on the floor by them. "And _THEN_, the stupid _wall _breaks down, my ladder snaps in half, and I have absolutely _no choice _but to come here! So don't get all _huffy _about – "

Candace blinked. "Wait...Hogwarts...This is _England_?"

"Well, technically, Scotland," Ferb pointed out.

Candace's mouth fell open. Her pupils dilated. "_Meep."_

Hermione lifted an eyebrow. She looked to the gaping hole where the Panic Room apparently led to. "Wait a second...Isn't anyone_ else_ the least bit curious as to why their house connects with Hogwarts?"

"Well, Hermione," Harry laughed, "we've got bigger problems at the moment."

Hermione also crossed her arms and glared at Candace. "And how exactly did _you _survive a few months trapped in a dark tunnel without food?"

Candace rolled her eyes. "Well, there was food. Unfortunately, it was all wild parsnips..."

As they walked past the unconscious troll, Phineas and Ferb clued Candace in on their situation. Just as the last of them had stepped through the door, and into the next chamber, the doors snapped shut.

Flames sprung up in a circle around them, trapping them inside. They could see another set of doors ahead of them, but the heat of the flame was scorching.

"We're trapped!" Candace shrieked. "Look what you've done _now_, dweebs!"

"Wait!" Hermione exclaimed. "There's a table, with some bottles!" She ran forward and began examining a piece of parchment that was on the table. "It's a logic puzzle! Here," she said, giving the paper for Harry to read.

Harry had barely finished the first sentence when Ferb poked his shoulder. Ferb read the paper, rubbed his chin in thought for a second, and then picked up two bottles. He gave one to Hermione and one to Harry.

"Already?" Harry asked, impressed. "Wow."

Hermione scoffed. "_I_ could have done that _just_ as fast as Ferb."

"Okay..." Harry said, thinking. "So, Hermione's will take people _back through _the flames, to the troll and stuff?"

"Right!" Hermione said. "Ron and I will get help from the other teachers."

Harry shook his bottle. "There's only enough here for _one_ person, though. Three of us have to stay behind."

"Fine by me," Candace said quickly.

Phineas looked back slyly at the troll room. "Well, maybe not..."

Hermione and Ron gave another shove, and the troll's club slid over the magical fire, making a very usable bridge. It was long enough that it spanned both sides of the fire, so now anybody could walk back and forth as they pleased.

"We'll be back with all the teachers we can muster!" Hermione promised, before she and Ron waved bye, and ran back out towards the chess chamber.

"Ready?" Harry asked.

"Ready!" Phineas replied.

Ferb gave a thumbs-up.

"Nuh-_uh_," Candace said, crossing her arms. "This is getting _weird _enough – I don't want to see what's on the other side – "

The fire blazed up and roared threateningly. Candace jumped and screamed, running past the three boys and over the fire.

Harry, Phineas, and Ferb held hands to steady the others as they crab-walked across the troll's club. Candace was waiting, terrified, at the doors on the other side.

Harry took a deep breath and flung the doors open.

Everybody stepped inside, and the doors closed behind them.

Everybody gasped.

It wasn't Snape.


	24. THE BIG FIGHT!

A/N: Wow! The big Boss chapter up now! I've got to say that this Crossover has been _great _fun to write, and even more fun to see how much people appreciate it! If you're reading this, please please please please leave a review!

I don't own Phineas or Ferb or Harry Potter. Now get ready for Perry the Platypus, Doctor Heinz Doofenshmirtz, Harry Potter, Phineas Flynn, Ferb Fletcher, and Professor Quirrel/Voldemort to face-off!"

It wasn't Snape.

It was Quirrel.

"You?" Harry asked dumbly. "Why?"

"I'll explain later, Potter." Quirrel waved his wand, and ropes sprang up to bind all four of the children.

"Now, quiet," Quirrel commanded. "I have business to attend to."

It was just then that Harry, Phineas, Ferb, and Candace saw something big and shiny sulking in the shadows. The Mirror of Erised.

Quirrel began circling around the Mirror like a starving vulture. "I don't understand...Must I _break_ the Mirror? Is the stone _inside_?"

Harry, Phineas, Ferb, and Candace shuddered as they heard another, different voice.

"_Use the boy_," it said, in quiet, hissing tones. "_Use the boy_..."

"Which one?"

A rather long pause.

"_There's more than one_?"

"Er...well...yes, Master."

Phineas snickered. He turned to Ferb. "Well, that just completely ruined the mystique of his statement."

Harry then became very worried. He, for one, knew that if he looked in the Mirror of Erised, he would see himself finding the Stone. Would he be strong enough to not tell where it was?

But Quirrel first took Candace and shoved her in front of the Mirror.

"Ah! These are _designer jeans!_" she gasped in protest, as she skinned her knees on the floor.

"_What do you see in the Mirror_?" Quirrel demanded fiercely.

Candace looked inside. Her smiled widened.

"YESSSSSS!" she cheered. Candace began doing a little dance in the Mirror. "You are totally BUSTED!"

Quirrel was confused. "What do you see? Where is the Stone?"

"Okay, dude, I have, like, _no _idea what you're talking about," Candace said with an eye roll. "I'm lookin' right at _TWO BUSTED BROTHERS! YEAH!_"

"You are of no help to me!" Quirrel snarled, shoving Candace back against the wall and summoning ropes again. He grabbed Ferb by the shirt and held him in front of the Mirror.

"_Where is the Stone_?" he demanded. "_What do you see?" _

Ferb looked into the mirror, blinking. He smiled and waved at whatever he saw.

Quirrel shouted with rage and shoved Ferb back with the others and tied him again.

"All right, _Flynn_!" Quirrel said, the words dripping poison. He grabbed Phineas and gruffly pushed him in front of the mirror. "What do you see?"

Phineas tried not to look – he was sure that he, like Harry, would see himself finding the Stone, and then everything would be over. He _hated_ himself right now – for the first time, he hated himself for coming to Hogwarts. He was a Muggle. He was a _Muggle_.

But Phineas looked, and, to his surprise, the image in the mirror hadn't changed since he first saw it in the Restricted Section.

Reflection-Phineas was holding a wand: a _true _one. A real, magical wand. Reflection-Phineas's cloak swirled around him as he pointed his wand in the air, and brilliant sparks came out.

In the Mirror of Erised, Phineas saw himself. As a wizard.

The hissing, quiet voice returned again. "_What does he see_?"

"Well?" Quirrel demanded.

"I'm a wizard!" Phineas blurted with joy, still looking at himself in the Mirror.

"_What_?" Quirrel asked, blinking in true surprise. "Nonsense. Where's the _Stone_, Flynn?"

"I...I mean, I see myself. As a really _great _wizard. Like Dumbledore!"

"_Great_!" Quirrel sighed. "None of you are any help!"

"_Wait...wait..." _the hissing voice came back. "_He lies, I believe...he lies..._"

"Where's the Stone, Flynn?" Quirrel shook Phineas by the scruff of the neck.

But Phineas couldn't see anything besides his own magical ability in the Mirror. His reflection twirled its wand and cast spells left and right, not even complicated ones, but _real magic_. Phineas felt a terrible pang of longing watching the display.

"_Wait..._" the hissing returned. "_Wait...what? I know he lies, Quirrel, but...it is difficult...And none can hope to best __me__ with Occulmency...But he _must_! It makes no sense!"_

"What, Master?" Quirrel asked, confused.

"_No!" _came the astonished gasp. "_He does __not__ lie! He sees himself as a wizard! WHAT IS THE MEANING OF THIS? He was Sorted into Ravenclaw, correct? And there is no way that a _Muggle_ could hope to enter Hogwarts, of course..._"

It was at this moment that fate chose to be even more ironic than usual.

_CRAAAASHHHHHHH!_

"All right! Bow down before me!" Doctor Doofenshimrtz yelled, jumping through the hole in the wall that he had just broken. He was brandishing his Duct-Tape Inator, and decided to point it at Quirrel, the only adult in the room.

"Right!" Doofenshmirtz yelled again. "Where is Perry the Platypus?"

A very, _very_ long pause.

Quirrel pointed at the four bound children, enraged.

"I'm kind of in the _middle _of something here!" Quirrel said obviously.

Doofenshimrtz observed the situation: Ferb, Candace, and Harry, tied up against the wall. Phineas being held in front of a large mirror by an angry turban-wearing man.

He coughed, embarrassed. "Oh...okay..._sorry_, dude, I just wanted to get past that stupid _moat_, and this was the easiest tunnel to dig..." He tossed a shovel to the side as he said it.

"_Who is that_?" the hissing demanded.

"Er, a Muggle, Master. He apparently dug under the moat and is looking for a Perry the Platypus."

"_Kill him!_"

"Whoa, whoa, whoa!" Doofenshmirtz yelled angrily. "I'm just here to make my nemesis foil me and my evil plot! And if you're going to pit yourself against me," Doofenshimrtz said, raising his Duct-Tape Inator and grinning manically, "prepare to eat DUCT TAPE! HAHAHAHA_HA_!"

He pulled the trigger.

A puff of smoke escaped the barrel of the Duct-Tape Inator.

_"Uh-oh!" _Norm's voice drifted in from somewhere beyond. _"Looks like someone forgot that technology doesn't work –"_

"Shut up!" Doofenshmirtz snapped in the direction of Norm's voice.

Quirrel sneered at Doofenshmirtz and, after a short pause, sliced his wand through the air and sent a spell rushing towards him.

However, it was at this exactly moment that Perry the Platypus kicked open the hidden passage above the chamber and fell through.

Just as Perry landed on the ground, the spell intended for Doofenshmirtz hit him. However, this particular spell was intended to affect humans, and Perry suffered no adverse effects.

Except for the fact that he was now in front of the three Flynn-Fletcher children, as Agent P.

Phineas blinked. "Perry?"

"_PERRY THE PLATYPUS_!" Doofenshmirtz yelled in triumph. "Well, it looks like all your little platypus _running away_ and _refusing to foil my plot_ has all been in vain!"

"_Wait!_" the hissing voice came back. "_Quirrel! Let me see what is happening!_"

"Master!" Quirrel protested, looking worried. "You are not strong enough!"

"_I am strong enough for this..._"

Quirrel, very slowly, took his hands and began to unwrap his obnoxious purple turban.

Harry gasped. His scar burned in pain.

Candace cringed. "_Eww! Gross!_"

Phineas raised an eyebrow.

Ferb blinked.

Perry the Platypus's eyes went very, very big.

Stuck to the back of Professor Quirrel's face...was _another _face.

Harry gulped. "Voldemort..."

Doofenshmirtz backed up a bit. "Okay, dude, that's the sort of thing you want to get _removed_."

"_Silence, Muggle_!" Voldemort snapped. His snake's eyes darted back and forth at the assembled group of people. He stopped at Perry.

_"What is __that_?" he demanded.

Phineas brightened up. "That's a platypus! He's our pet, Perry. And apparently he's some sort of secret agent..."

Doofenshmirtz scratched his head. "Your pet? But...he's my _nemesis_..."

"_So, let me get this straight..." _Voldemort said._ "In this room is Quirrel, a Half-Blood, something called a platypus, and not just one...but _three _Muggles?"_

"What's a Muggle?" Doofenshmirtz asked.

"_You! You and your filthy, unworthy, sort of people who..._"

While Voldemort and Doofenshmirtz were yelling at each other, Phineas snuck back to Harry and the rest. He undid their ropes and was attempting to usher them back out the doors.

Unfortunately, Voldemort glanced over in their direction and saw them.

"_Quirrel! You idiot, the boy and his friends are escaping_!"

Quirrel spun around and waved his wand, causing the doors to lock magically. He was about to start killing all of the children, when something furry shot at him.

"AHHH!" Quirrel yelled, as Perry the Platypus, protecting the host family that he'd come to love, had delivered a spinning kick to Quirrel's head.

"DIE! DIE, you stupid...uh..._whatever you are_!" Quirrel shouted, firing spells at Perry the Platypus.

Then Quirrel was hit on the head with something very heavy and hard.

"Hey!" Doofenshmirtz shouted angrily. "That's _my _nemesis!" He began swinging his malfunctioning Duct-Tape Inator at Quirrel and Voldemort.

But Voldemort hadn't chosen a _complete _weakling for a host body. Quirrel fended off both Perry the Platypus's attacks and those of Doofenshimrtz.

"Don't you _dare _run away, Potter!" Quirrel screamed. He advanced on Harry and his friends, sending spells flying in every direction.

Perry, with a flying leap, delivered multiple slaps to Quirrel's face with his platypus tail. When Quirrel turned around to try and hurt Harry and the Flynn-Fletchers, Perry tail-slapped Voldemort's face as well.

_"AHH!_" Voldemort screamed. "_You will DIE for that, Platypus_!"

Harry and his friends decided to join the fight. "Why does your platypus fight so well?" Harry asked Phineas.

Phineas shrugged. "Dunno. I guess he's a secret agent or something."

"_Petrificus Totalus!_" Harry aimed at Quirrel, who blocked it with a Shield Charm.

"_Densaugeo_!" Phineas tried. This one actually caught Quirrel off guard, and hit him in the back. Almost immediately, his front teeth began to grow at an alarming rate, giving him the appearance of a creepy rabbit with a snake grafted onto the back of its head.

Suddenly, there was a great banging from the locked doors behind them.

"Potter! Phineas!" Professor McGonagall called. "We're here with the Heads of Houses, and we're coming to help! Give up now, Quirrel, Dumbledore's here!"

_"Dumbledore_!" Voldemort hissed with a note of fright in his voice. The teachers were furiously casting spells at the door, which made continuous banging noises as they tried to open it. "_Quirrel, you useless idiot, if you do nothing else tonight, kill the Potter boy!" _

Quirrel, upon hearing Voldemort's wishes, threw himself at Harry. Harry hadn't expected an attack of such, and so Quirrel was able to grab onto his arm.

As soon as they touched, Quirrel's hand sprouted huge blisters and began to disintegrate.

"AHH! Master, I cannot touch him!"

"_Then kill him, fool!"_

But Harry was clever; he reached up and grabbed Quirrel's face, which began to break into dust as soon as he touched it.

Quirrel was now panicking, which was understandable, since he was apparently turning to dust for no reason. He sent spells flying in every direction, at every person at once, trying to do something, save himself, obey his Master –

_BAMMM!_

The teachers slammed the doors open, led by Dumbledore, just in time to see one other thing make just as much noise as the doors, as it exploded.


	25. Phineas is Forced to Tell the Truth

A/N: Well, the very first book of my series is almost completed! At the beginning of the last chapter, I'll give the name of the next 'book'. I've decided that my Fanfiction titles will follow the same format. This is _Hogwarts? How Serendipitous!_ The next one will be _Chamber of Secrets? How ..._.! Something. I haven't decided yet. I don't own Harry Potter, blah blah blah, please read and review!

Minerva McGonagall, Severus Snape, Filius Flitwick, Pomona Sprout, and Albus Percival Wulfric Brian Dumbledore burst in the room in which the two forces were battling it out.

When they entered, however, they found that the action had completely vanished, and were instead left with several very odd things going on at once, including a teal-colored animal in a fedora, a dissolving, ex-Defense Against the Arts Teacher, a pharmacist, and a teenage girl Muggle.

Filius Flitwick stepped up and began addressing these issues. He turned to the first thing he noticed.

"Flynn!" he gasped, as did all the other teachers. A cruel realization was settling upon them.

Phineas Flynn kneeling on the ground, bending over the remaining bits and pieces of his mechanical wand. One of Quirrel's spells had hit it, and the whole wand had exploded. But now that the teachers were here, they saw all the mechanical parts strewn about the floor.

McGonagall picked up a small computer microchip. "This is a Muggle artifact!" she gasped. "But...but..._surely_...it's _impossible_!"

"Flynn!" Severus Snape barked. "I demand that you tell the truth! _EXPLAIN YOURSELF!"_

Phineas took a deep breath in. He began to speak very slowly.

"I am actually a Muggle...who snuck on the train in Ferb's suitcase...and built a mechanical wand to fake magic."

It was the awkwardest silence in the entire documented history of magic.

"He was telling the _truth_?" Professor Sprout squeaked, her voice suddenly as high as Flitwick's.

"You were telling the _truth_?" Professor Flitwick asked incredulously.

Phineas nodded solemnly. "Yes. Yes I was."

"_Inside _your brother's suitcase?" McGonagall flinched. "Well, no _wonder_ your head is a triangle."

"All right, moving on!" Flitwick announced.

_Whishhhhhhhhhhh_ went our field of view as it zoomed over to show a new person.

"Okay, people," Candace Flynn protested, realizing all the attention was now upon her. "I have, like, _no idea _what the heck is going on here. Two-faced turban dude wanted a rock – this is all I know."

"Are you a Muggle?" Dumbledore asked.

"Uh, if that means _normal person_, then, _yes_!" she said rudely, putting her hands on her hips.

"What are you doing at Hogwarts?"

"Well, when I came here, I was trying to get a stupid _plant_ off of my arm. Then my brothers showed up with some British dudes and almost got me _killed_!"

"Moving on!" Flitwick announced.

_Whishhhhhhhhhhh..._

Perry the Platypus was standing on his two legs, wearing his fedora, evidently confused.

"That's our pet Platypus Perry!" Phineas said happily.

Sprout scratched her head. "Why... is it wearing that..._hat_?"

Perry's heart sank. He would have to leave the boys now –even Candace, and Linda, and Lawrence. He would be reassigned to a new host family. And he would never see them again, now that he was exposed as Agent P.

"Oh, well, Quirrel was casting this spell, but our platypus got in the way and it hit him instead!" Phineas informed them. "I dunno_ what _on Earth the spell was supposed to do, but it apparently turns platypuses into Secret Agents!"

Perry looked up with newly restored hope. If everyone thought that it was a_ spell _that had caused it...

"Well," Dumbledore said, taking out his wand, "if it was a spell, than _this _charm should restore your platypus to normal. If it doesn't, your pet is truly a secret agent."

Dumbledore began chanting in an ancient language, and smoke rose around Perry, obscuring him from view.

Perry felt the magic, but he was actually a Secret Agent, so it didn't do anything. But, what the heck? The smoke was hiding him, so he just took of his fedora and plopped down on all fours.

"_Et Finite_!" Dumbledore finished, ending the spell. He waved his arms and the smoke dramatically dispersed.

Perry was Perry the dumb platypus again, the one that didn't do much.

He made his platypus chittering noise, and went over to be by Phineas.

"Well, that's resolved. Moving on!"

_Whishhhhhhhhhhh..._

Harry was kneeling on the floor, holding the last remaining piece of Quirrel in his hands, which dissolved even as the teachers turned their attention to him.

Harry glanced around him at the Quirrel Dust sprinkled on the floor, in utter confusion. "He...er...I...what?"

"Nice work, Potter! Moving on!"

_Whishhhhhhhhhhh..._

Ferb was standing in a fighting stance, his two shoes tied together to form a pair of nun chucks.

He glanced at the teachers, and then twirled and snapped the nun chucks.

"Very good! Moving on!"

_Whishhhhhhhhhhh..._

"Who the HELL are you?"

"Me? I'm...I'm Heinz Doofenshmirtz!" Doofenshmirtz picked up his Duct-Tape Inator, which had a huge dent from hitting Quirrel.

Snape wrinkled his nose. "A pharmacist?"

"Really?!" Doofenshmirtz asked angrily. "_Really_? I'm an evil scientist, the most brilliant mind on earth, and FUTURE RULER OF THE ENTIRE _TRI-STATE AREA!"_

Sprout gave him a funny look. "You must be that disturbed creep from Danville."

"Oh, so you've heard of me!" Doofenshmirtz said delightedly.

Phineas blinked. "There's a mad scientist in Danville?"

"Yeah!" Doofenshmirtz said. "And my brother is the Mayor!"

"But you are a Muggle?" Dumbledore asked.

Doofenshmirtz crossed his arms. "Well, I just got this lecture from a snake man who was stuck on the turban guy's head about it, so ... yeah. But I'm not, like, the _scum of the earth_, or the _brainless, useless_, _animals who deserve to be slaughtered without mercy_."

McGonagall gasped. "He-Who-Must-Not-Be-Named?" She cast a worried look at Dumbledore.

Dumbledore nodded solemnly. "It appears that Voldemort did not die that night, eleven years ago. I suspected as much." He cleared his throat. "My apologies, Mister Doofenshmirtz, but as you are a Muggle I will be forced to perform a Memory Charm on you."

"Oh, that's fine, I ... wait, _what_?"

"Otherwise I would break the Secrecy Stature," Dumbledore said impatiently. "It will only take a second, and you will forget everything you saw here."

Doofenshmirtz staggered backwards, putting up his hands to defend himself. "Uh, I'd rather _not_..."

Dumbledore shot a Memory Charm at him.

"Hey!" Doofenshmirtz yelped, shielding himself with his Duct-Tape Inator. The Memory Charm bounced off and hit the wall instead.

Dumbledore frowned and tried to Stun Doofenshmirtz many times, but Doofenshmirtz shielded himself with the Duct-Tape Inator and ran screaming _"NO, I'm a schnitzel!" _through the hole he had dug previously.

"Are we pursuing him, Headmaster?" McGonagall asked.

Dumbledore pocketed his wand. "Not yet, Minerva. A Muggle, I daresay, will not make it very far in the time we shall allot to him."

Flitwick raised an eyebrow. "I hate to object, Dumbledore, but this deranged Muggle managed to make it into Hogwarts. If we let him go..."

"We have more pressing matters," Dumbledore said. "I believe that Harry Potter, Ferb, Phineas, and their sister, have been quite valiant and deserve some rest. If you would please take them to the hospital ward, I will consult my partner on Alchemy as to the future of the Stone."

"_Thanks_, _sir_," Harry mumbled, before exhaustion claimed him, and he collapsed on the floor.


	26. Hogwart's First Muggle Student?

A/N: I don't own Harry Potter or Phineas and Ferb. Read and review!

Phineas opened his eyes in the Hospital Ward. The white sheets, walls, and floor made his eyes hurt a lot.

When he got them to focus, he was able to see Ferb reading _Paradise Lost_ in his bed. Ferb noticed he was awake and gave him a thumbs-up.

"Hey, bro," Phineas said, sitting up. Just then, he noticed that they weren't alone.

"Professor Dumbledore? What're you doing here?" he asked, blinking.

Dumbledore laughed. "Well, just having a private talk with Harry. But now, I suppose, we need to talk a little about _you,_ Phineas Flynn."

Harry turned over in bed and looked over what seemed like half the candy store, which was piled on his bedside table. "Hey, guys," he said weakly.

Dumbledore crossed to Phineas's bed. He shook his head. "Phineas, Phineas, Phineas..."

Phineas looked at the ground. "I know. I shouldn't be at Hogwarts."

"Let's not jump to that topic quite yet," Dumbledore said. "Firstly, I would like to congratulate you, Phineas. You are the first Muggle to break into the school and earn an education here since...well...the school was founded."

Phineas couldn't help but smile. "Well, there's always a first time for everything."

Ferb nodded wisely from his bed.

"You managed to keep up the deception for almost the entire year, long enough to earn your exam scores. You were Sorted into a Hogwarts House, hoodwinked the staff and students, and devised a way to fake magic in less than a half hour. That is no small feat." Dumbledore smiled. "You fit well into the House of Ravenclaw, Flynn."

"Thanks, sir. It was fun, at least for a year."

"I'm not finished yet, Phineas," Dumbledore said patiently. "I have been thinking it over for quite a while, and still face a tough decision: do you stay at Hogwarts, or are forced to return?"

Dumbledore lowered his voice and peered at Phineas over the rim of his half-moon spectacles. "Phineas, personally, I would like you to stay, but it is not the question of my wanting, but one of _your_ safety. Bad things are on the horizon, Phineas," Dumbledore said, quietly and darkly. "You've already witnessed Lord Voldemort nearly return, and I doubt that he will give up after this small setback. There is only one thing that Lord Voldemort hates more than Muggle-borns and Mudbloods – true Muggles. And the thought of a Muggle attending Hogwarts, the school where he himself learned magic, is sure to infuriate him beyond anything else, if it hasn't already."

Dumbledore sighed and shook his head. "But I cannot decide the worse evil: if you stay or if you are forced to leave. I leave it up to you."

Phineas practically shot straight out of his bed. "You mean, I can choose? I could stay if I wanted?"

"If you stay, you would be endangering your life beyond any other student, perhaps even that of Harry," Dumbledore warned, trying to make Phineas see sense, but he knew it was pretty much all in vain.

"Oh, it's okay, sir," Phineas said, beaming. "There isn't any problem that can't be solved with a roll of duct tape and a jar of peanut butter. I'll stay here at Hogwarts with Ferb. If Moldywart comes after me, I'll be ready."

"That's _Voldemort_," Harry enunciated.

But Dumbledore was smiling. "Very clever, Phineas, though I suggest you avoid that particular name in public."

"DUMBLEDORE!" Severus Snape shouted, storming into the hospital room. "Did I just hear you correctly? Are you letting this...this...Muggle _stay_?"

"Severus, my decision was thought out for a very long time, and very – "

"JUST STOP!" Snape spat, looking at him, and then Phineas with unconcealed hatred. "Dumbledore, this is beyond insanity! This is a school of _magic_! Have you lost your _mind_?"

"Allow me to speak with Professor Snape in private," Dumbledore told the children. "I will be back shortly."

When Snape and Dumbledore were outside of the hospital wing, Snape slammed the doors shut. He held his hands behind his back and began pacing back and forth in front of Dumbledore.

"Well?" Dumbledore asked politely.

"He can't!" Snape exploded. "He can't stay! What Flynn needs is a Ministry reprimanding and a one-way train ticket! This is an _outrage_, Dumbledore!"

"Please listen to my reasons, Severus," Dumbledore pleaded. "Before you decide whether they are right or wrong."

Snape made a grunting sound under his breath, perhaps, _Proceed_.

Dumbledore gestured at the closed hospital wing doors. "You are concerned for Hogwarts's reputation, correct? Do you think that we will be looked down upon?"

"Of course!" Snape shouted, stopping in his tracks. "This is a _school of magic_, Dumbledore!"

"But what if Phineas was able to prove himself competent on his exams? What if he scored quite well? Why would that be disgraceful to Hogwarts, if he were able to meet the curriculum?"

"Did he?" Snape asked sharply.

"As a matter of fact, yes."

Snape made the grunting noise again. He shook his head and resumed pacing. "And what of Flynn's own safety? Does he _care _about the danger his life would be in? Those of his friends and family? The Dark Lord almost returned last night. When the Dark Lord _does _return, he'll get more than the train ticket I proposed earlier."

"And what if, Severus," Dumbledore countered gently, "we forbid him?"

"Good riddance, I'd say!" Snape spat.

"Do you really think a little thing like an official expulsion is going to keep Phineas away? No, Severus, both of us know that. He'd come back, probably trying something even more risky than the charade he pulled this year."

At this, Dumbledore waved his wand, and the hospital wing doors opened a bit, just enough to let Snape see Phineas, Ferb, and Harry bending over a large blueprint.

"Well, I see what you're saying, Ferb," Phineas told his friends, "but we have to take into account the hot, molten core at the center of the Earth. And Harry, I understand your theory, but the near-absolute zero temperatures of space also make that an impossibility."

Then all three of them looked over and saw their meeting was being spied upon. Phineas quickly stuffed the blueprint behind his back sheepishly.

Dumbledore smiled at them and closed the doors again. "Do you see what I mean, Severus? Phineas will come back, no matter what."

"Then have the Ministry keep tabs on the brat!"

"I doubt that even the Ministry's finest Aurors could keep Phineas Flynn away from his brother, and away from Hogwarts."

Snape seemed incapable of speech. He made a few sputtering noises, his face becoming an unhealthy shade of green.

"Do you understand, Severus?"

Snape bared his teeth for a few seconds, but finally gave a quick, angry nod.

"Good," Dumbledore said.


	27. How Gryffindor Won the House Cup

A/N: I don't own Harry or Phineas or Ferb.

The nurse wasn't keen on letting any of the students go the next morning, especially Phineas and Ferb.

"Come, Poppy, they need to attend the End of Term feast," Dumbledore tried to reason.

"But...but their eyes are three times the size they should be at their age..."

"They need to see how they did on exams, as well. You know as much."

Madam Pomfrey frowned. "But...but their eyebrows aren't attached to their head..."

Eventually, Dumbledore got them out of the hospital wing.

As Harry, Phineas, and Ferb stepped into the Great Hall just before the feast, the entire Gryffindor and Ravenclaw tables jumped up and started swarming their respective members. The three boys tried to calm down their Houses and told them all about their adventures in the Forbidden Corridor; the dog, the plant, the room of keys, and the big encounter with Quirrel.

Then, of course, all four of the Houses sent people to ask Phineas constantly if he was a Muggle or not, which Phineas wholeheartedly agreed to, and stressed that he had never denied it during the school year.

As Dumbledore stepped up to his podium, the school seemed to settle down, although everyone could still hear a faint buzzing sound of excitement in the background.

"Another year gone!" Dumbledore announced happily. "And I must trouble you with an old man's waffle before we sink our teeth into our delicious feast."

"What a year it has been! Hopefully, your heads are a little fuller than they were...you have the whole summer ahead to get them nice and empty before next year starts..." Dumbledore seemed embarrassed to continue his speech, about the House Cup. It was a known fact that Slytherin had been winning for an insane number of years.

"Now, as I understand it, the House Cup needs awarding, and the points stand thus: Gryffindor, in fourth place, with three hundred and twelve points; Ravenclaw in third, with three hundred and fifty two; Hufflepuff in second, with four hundred and twenty six; and Slytherin, in first with four hundred and seventy two."

The Slytherins began a raucous cheering that made all the plates and glasses in the Great Hall shake. They high-fived each other and gave the others pats on the back.

"However," Dumbledore continued, causing everyone to turn and stare at him, wondering what the 'however' was about.

"However, there are some last-minute points that need to be dished out." Dumbledore looked down at a small list he had on his podium. "First, as some rumors have begun, our very own student, Phineas Flynn, has just announced to the teachers he end of a rather clever deception he had been staging. It is true: Phineas Flynn is a Muggle."

At this, the majority of the school, that hadn't known or suspected, let out a collective gasp. The Slytherins began booing and hissing, but they were soon drowned out by the clapping and cheering from the other Houses, which were amazed beyond belief.

"Yes," Dumbledore said. "Phineas Flynn figured out how to fake magic with a mechanical wand in less than a half-hour, on the train to Hogwarts, after sneaking there in his brother's suitcase. Using this 'wand', so to speak, he passed all his exams with f lying colors. I would like to announce that Phineas Flynn _will _be remaining at Hogwarts to study magic, with his brother, Ferb Fletcher."

"_Whooooooooooo!" _A student cheered. Others whistled or clapped, and only the Slytherin table, which watched him contemptuously, made no noise. Everyone else was overwhelmed with this memorable event.

"I would like to award Phineas Flynn and Ferb Fletcher for their outstanding contributions to the grand Quest that was undertaken just a few nights ago: fifty House points each!"

"We beat Hufflepuff!" Penelope Clearwater cheered. "We're in second now!"

Harry turned around from the Gryffindor table. "But you still didn't win it. Why are you so happy?"

"Who cares if we didn't win?" Phineas asked. "Our House just got recognition by the rest of the school! That's an uncommon occurrence!"

"Please!" Dumbledore shouted over the hubbub, which gradually died down again. "Now, to continue. To Ronald Weasley, Hermione Granger, I award fifty points each for their incredible bravery and dedication to saving their school!"

"That's a hundred points!" Hermione nearly squealed. She looked ready to burst into tears of joy.

Dumbledore found Harry's face in the sea of students, and smiled at him. "And, of course, you have all heard of Harry's defeat of Quirrel and Lord Voldemort." The entire school shuddered at the name. "For his heroic actions, and unwavering bravery, I award sixty House Points!"

"We're tied with Slytherin!" Ron shrieked.

Harry held his breath...just one more point, and they'd win...one more...one more...

Dumbledore looked around the school. "Oh...er...um..."

"I just realized...Neville Longbottom didn't try and stop the students in this story. They were already wandering the halls..." Dumbledore looked around nervously, at the anxious Gryffindor table. "I guess...I was going to give points for that, but...that kind of...fell through..."

He threw a begging glace at McGonagall, who shrugged, unable to think of anything...

Suddenly, there was a great coughing in the Great Hall. The tension had been too much for a young Hufflepuff boy, who had accidentally started choking on a piece of bread. The Hufflepuff fell off of the bench, clutching his throat.

"LET ME THROUGH!" Hermione screamed, leaping over the Gryffindor table to the Hufflepuff one, and kneeling down by the Hufflepuff's side. He was rapidly turning blue and didn't seem able to cough.

Hermione took out her wand and pointed it quickly at his throat. "_Anapneo_!"

The Hufflepuff stopped clutching his throat, and blinked rapidly. He sat up and coughed a little, but the piece of bread had vanished.

He looked at his benefactor. "Thanks," he said simply.

It was so quiet in the Great Hall that one could have heard a pin drop.

"FIVE POINTS TO GRYFFINDOR!" Dumbledore roared suddenly. "For Miss Granger saving the Hufflepuff boy!

It was as if a bomb had gone off in the Great Hall. Hufflepuff, Ravenclaw, and Gryffindor were all clapping and cheering like they'd never done before, to celebrate the downfall of Slytherin House.

"AND GRYFFINDOR TAKES THE CUP!" McGonagall screamed happily, standing up and doing a fist pump.

The noise lasted for what seemed like forever. Everyone but the Slytherins stood up and managed to pick up Harry, Ron, Hermione, Phineas, and Ferb, carrying them like champions above their heads.

"Muggle power!" an unknown Gryffindor called out, as he was supporting both Phineas and Hermione at the same time.

"Bravery and smarts triumph!"

"Wow, Harry," Ron laughed. "Isn't this great?"

Harry couldn't answer. He was beaming from ear to ear, and wasn't about to stop.


	28. What Happened to Doof and The Very End

A/N: Last chapter! What a memorable event! Thank you to all my faithful readers and future ones, if indeed there are any. I don't own Harry Potter or Phineas and Ferb.

"He's getting away!" McGonagall shouted, firing another spell at the white lab coat that was hiding behind a large boulder.

"_Lady, what __is__ your problem_?" Doofenshimrtz asked from behind his barricade. He put his back to the rock and listened.

"There, behind the boulder!" Dumbledore announced. "_Evanesco_!"

The boulder vanished like a mirage and left Doofenshmirtz open to any kind of attack.

"You will rue the day you incurred the wrath of _Heinz Doofenshmirtz!_" he screamed, shaking his fist at them. Then he screamed like a little girl as the top of his head was singed with a spell from Flitwick.

"_Aaaiiiiiiiiiiii!_" he shrieked, running to the edge of the castle, where the beach met the water. He paused for a moment, remembering the Secret Agent beneath the waters...

_"Stupefy!"_ Sprout cast, and it burnt a hole in his lab coat.

He jumped in and began swimming as fast as he could.

Almost immediately, the Giant Squid of the Hogwarts Lake had trapped him in his tentacles. Carrie the Cephalopod dangled Doofenshmirtz over the water, waiting for the teachers to catch up and trap him.

Doofenshmirtz looked pleadingly at his captor. "Carrie the Cephalopod! What are you doing?"

Carrie made a weird squid gurgling noise, accompanied by a nasty glare.

"Oh, so you're still upset about _that_? Geesh, I've told you that was an _accident_, like, a million times already!"

The squid lifted up an arm to reveal four tiny scars, all in a row.

"You _never _healed? Well, I'm sorry, Carrie the Cephalopod. But _please please please please _let me go!"

The squid shook its head.

"Carrie the Cephalopod, you have thwarted me twice already, not counting the time where I crossed in the M-OTOR-BOAT." He counted on his fingers and shows Carrie angrily.

"Do you know what they will do? They will capture me and _steal _my memories. Do you support _thievery_?"

Carrie thought about it.

"Please, Carrie the Cephalopod, we all make mistakes. Learn to forgive and move on. _Please_!"

"Cast the charm!" McGonagall shrieked. Dumbledore fixed his wand on Doofenshmirtz's flailing figure…

Carrie the Cephalopod flung Doofenshmirtz across the lake and into the grove of trees on the opposite shore. The spell sailed past the lake and hit a building.

"_CURSE YOU, _and thank you_, CARRIE THE CEPHALOPOD!" _Doofenshmirtz yelled from the shore.

Dumbledore stopped short. "He got away!"

All of the teachers gasped.

"Inconceivable!" Flitwick yelled.

McGonagall shook her head. "There goes the most _idiotic_ Muggle I have ever seen. Who knows what damage he will cause with that information?"

"Somehow, Minerva," Dumbledore said as everyone turned to reenter the castle, "I think he would have caused the same amount _without _that information. At least, to himself."

(A/N: If anyone is confused about the Doof/Carrie relationship, great! That will be visited later on in my 'series'.)

_Elsewhere in Britain/Scotland…_

The train ride back to King's Cross was delightful: all the Ravenclaws were literally attached to Phineas's and Ferb's sides the whole while, congratulating them and asking them questions about the Muggle world, and about Phineas's deception. Someone mentioned it going down in the Daily Prophet newspaper. Candace was aboard the train, too. She had wanted to skip the feast, obviously to avoid meeting all those _freaks_, as she put it.

"MOM! DAD!" she screamed, leaping out of the train window and throwing her arms around her parents. "I MISSED YOU SO MUCH!" she sobbed, and then lapsed into the whole tragic story about the plant and the crazy two-headed turban dude.

Phineas followed quietly behind Ferb. Linda and Lawrence were watching him very suspiciously.

Linda grinned dryly. "I got your, um, _letter_ in the mail, Mr. Flynn. Seems like you kind of...snuck off without our permission, hmm?"

Phineas nodded. "Well, yeah. But the Headmaster says I can come back next year!"

"After your behavior, young man, I'll have to put deep thought to that topic," Linda told him.

"Mrs. Flynn?"

Linda turned around and blinked. It was not Phineas who had just addressed her, but a black-haired boy with conspicuous glasses.

"Yes?" she asked.

"Please let Phineas come back to Hogwarts," Harry pleaded on his friend's behalf. "School wouldn't be the same without him. He's brilliant, honestly! And he's made a lot of new friends, and...and learned stuff...and...and...seen so much..."

"That Muggle's fantastic!" Ron exclaimed. "Just imagine, he _made his own wand _on the train to the school! And it worked!"

Hermione, who stood to Ron's side, was silent until Ron gave her a hard shove.

"Er...yeah," she said, still cross. "Even though it's strictly against Hogwarts _rules_, not that anyone _cares_ about _those things _anymore."

Ron gave an even harder shove.

"Fine! Yes, Mrs. Flynn, he really is a brilliant student, _like myself_," she specified quickly. "And...yes, I'd be really disappointed if he couldn't return."

Linda lifted an eyebrow and took in all three of the students.

She sighed. "Fine. Phineas, you'd better thank your friends. I'll let you go to this weird school." Linda glared at Lawrence again, still kind of cross about the whole _Oh, and by the way, your adopted son is a wizard_ thing he had just pulled.

Candace, Ferb, Linda, and Lawrence began to walk to the pillar connecting platform Nine and Three-Quarters with the Muggle world. Harry and Phineas stayed behind.

"Some year, huh?" Phineas asked.

"Yeah! Really fun." He grinned. "But this summer will still be great."

"Summers are always great!" Phineas exclaimed. "Ah...Summer. Where do we begin?"

"Well, I'll begin by muttering some hocus pocus under my breath if Dudley becomes unbearable."

"But Harry!" Phineas said. "You got a pamphlet while entering the train that said you couldn't use magic while not at school."

"Yeah..." Harry smiled again. "But they didn't say we had to give them to our parents, now did they?"

It was Phineas's turn to smile. "No. No they didn't. How serendipitous."

A/N: It's so beautiful! What fun it was to write this first story! I hope that you all go out there and review my story, even if you absolutely hated it. Just give me a legit reason and I'll try and fix it. Watch out for _Chamber of Secrets? How Malicious!_ Coming to Fanfiction soon!

If you liked this story, and even if you didn't, go check out my other stuff. I have a Fanfiction called _Lauren Hartfield, Hufflepuff_, which is about a group of Hufflepuffs that get fed up with being called stupid and save the wizarding world after Harry kills Voldemort. I also have a Phineas and Ferb Fanfiction called _Try to Remember – The Lost Episode_. Remember that line from _Across the Second Dimension_? "Amnesia-Inator? I never built one of those. (Pause) And I would remember making something like that!" It's the lost Phineas and Ferb episode with the Amnesia-Inator!  
And if you want another great Phineas/Ferb/Harry crossover, read _Nothing Short of Insanity _by The QAS. Her story is also really good.

And heck, did I ever mention reviewing? Because you need to do it, if you haven't already. Bye!


	29. Epilogue

A/N: Hello, me again! Hope you liked the story. The sequel's up now, as most people know, but if you didn't, go check it out!

Now, I'm here to start a brand-new tradition with my Crossover series. I was going to have this little 'extra' for a character in my third book, but then a friend suggested that I make one up for every book. This is number one out of seven. Enjoy!

_Doobie doobie doo-ba,_

_Doobie doobie doo-ba,_

_Doobie doobie doo-ba,_

_Doobie doobie doo-ba,_

CARRIE!

…

He's a fully aquatic,

Beak-wielding mollusk of action!

_Doobie doobie doo-ba,_

_Doobie doobie doo-ba,_

He's a pink and squishy agent,

Who'll never flinch from a fray-ee-ay-ee-ay!

He's got MORE than just mad skill!  
He's got a fan club, mostly of krill!

And he likes to surface, when it's a warm, sunny day!  
…

He's CARRIE!

Carrie the CEPHALOPOD!

…

CARRIE!

…

_AY – GENT C!_


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